





































































* 



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The Modern boy’s Library 


Something to Make 


































THE MODERN BOY’S LIBRARY 
Edited by Eric Wood 

SOMETHING TO MAKE 
THE OUTDOOR BOY 
THE BOY’S WORKSHOP 
HOBBIES 


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Something to Make 


Edited by 

Eric Wood 

H 


With Many Working Diagrams 
and Illustrations 


o 


New York 

Funk and Wagnalls Company 




£ * 

i y* 

°~4 V. /?X<3 


Printed in Great Britain 

















EDITOR’S NOTE 


T HE Modern Boy’s Library has been designed 
to include volumes on every subject in which 
the boy of to-day is interested—which means that 
eventually there will be but few subjects not dealt 
with ! For the modern boy is keen to know about 
everything that happens ; anxious to try his hand 
at the making of things ; the joy of creation is 
behind all his dreams. 

Each of the books in the Library has been written 
by men—there are nearly as many contributors as 
there are chapters !—who are experts in their own 
spheres ; and, while every endeavour has been made 
to reduce even the most intricate subjects to sim¬ 
plicity, it must be remembered that some subjects 
are not to be treated in the style suited to the men¬ 
tality of the kindergarten ; and, after all, these books 
are not intended for the kindergarten. Moreover, 
it is worth remembering that the value of books lies 
in their knowledge-giving quality. We do not read 
books merely because they are there to read ; we 
study them in order to get to know something of 
which we were ignorant before. There are many 
things in the volumes of this Library that the average 
boy does not know ; they are here for his instruction, 
in language as simple as is possible consistent with 
accuracy. 

To give something for the boy to do, to know, 
to enjoy—that has been the threefold object behind 
the compilation of these books. 




Contents 


FAGK 

Section I.—ELECTRICAL THINGS TO MAKE 

1. A Wireless Telegraphy Set ... 9 

2. An Electric Machine. 41 

3. A Needle Telegraph Apparatus ... 59 

4. An X-ray Apparatus ..... 77 

5. A Fluoroscope ...... 92 

G. A Home Telephone ..... 93 

7. An Electric Fire Alarm . . . .117 

8. A Burglar Alarm ..... 121 

9. An Easily Made Electric Motor . . 125 

Section II.—MECHANICAL THINGS TO MAKE 

1. A Quarter-plate Camera .... 129 

2. A Changing-box for Hand Camera . .137 

3. A Cinematograph Camera . . . .143 

4. A Home Cinematograph . . . .149 

5. A Magnetic Compass. 155 

G. An Automatic Machine .... 159 

7. An Automatic Machine for Viewing 

Postcards. 1G3 

8. A Gramophone. 167 

VII 











viii Contents 

PAGE 

Section III.—SIMPLE MODEL MAKING 

1. A Distinctive Type of Model Aeroplane . 183 

2. A Handy Glass-cutter . . . .191 

3. A Model Cigar Boat . . . . .192 

4. A Model Transporter Bridge . . .195 

5. How to Make an Existing Model Boat 

Self-propelled ..... 202 

8. A Model Car ...... 205 

7. A Model Tube Railway .... 209 

8. A Model of “ Shamrock IV ” . . 215 

9. A Model Searchlight .... 223 

Section IV.—MISCELLANEOUS THINGS TO 

MAKE 

1. A Telescope ...... 227 

2. A Microscope. 235 

3. “ Hands Up ” . . . . . . 243 

4. How to Make a Diver .... 250 

5. How to Make a Catamaran . . . 252 

G. A Chess and Draughts Table . . . 255 

7. Shelters for Out-of-Doors . . . 258 

8. A Model Railway in the Garden . . 261 

9. A Cricket Bat Case. 282 

10. Things for Camp and Trek . . 283 










Something to Make 


Section I 

ELECTRICAL THINGS TO MAKE 


A WIRELESS TELEGRAPHY SET 


W HEN radio-telegraphy was first demonstrated 
to an astonished world the most wonderful 
thing about it seemed, to ordinary people, to be the 
fact that no wires were used to connect the sending 
and receiving instruments. This amazing thing— 
it seemed to be a veritable miracle—outshone all 
the other wonders of the system, and so the general 
public seized on the name “ Wireless Telegraphy ” 
and used it for this new method of talking at a 
distance. 

Though it is so popular the name is not a very 
good one, for there are many kinds of telegraphy 
that are “ wireless.” The army and navy ways of 
signalling with flags and lamps and mirrors are all 
of them more truly “ wireless ” than radio-tele¬ 
graphy, for, as we shall see, though no wires connect 
the instruments, there is a very great deal of wire 
used in what is known as “ wireless telegraphy.” 

Before we can proceed to the making of our 
apparatus it is necessary to understand how “ wire¬ 
less ” works, and so I propose to explain it in ver) T 

9 



io Something to Make 

simple language. To do this it will be necessary to 
leave out a deal of explanation that a scientist would 
think essential; but if wc understand the main 
facts clearly it doesn’t really matter how much or 
how little “ science ” we have in this article. 

Many of you will perhaps know how to make two 
very interesting pieces of electrical apparatus. One 
is a spark coil (in the article on X-ray Apparatus), 
and the other is a Wimshurst machine. Both 
these are capable of producing a current of very high 
intensity that can jump across an air gap of an inch 
or more. Though these two pieces of apparatus 
produce their electricity in quite different ways, the 
result is the same—the electricity leaps across the 
air gap with a crack and a blaze, like a miniature 
flash of lightning. (See pp. 41 and 77.) 

Now look at Fig. 1. Here I have shown a coil, 
with battery and spark gap. You will see that 
the spark gap is connected with the earth on one 
hand and with a kind of gridiron on the other. This 
gridiron represents an aerial. When you work the 
coil it is some while—a fraction of a second—before 
the current is strong enough to jump the gap. Dur¬ 
ing this time the aerial wires are charged up with 
electricity, which is trying to escape to the earth to 
join up with the earthed terminal, but can’t. When 
the discharge takes place across the gap the current 
surges down from the aerial so strongly that it over¬ 
discharges itself and back the current rushes and 
overcharges the aerial again. This takes place many 
times with tremendous rapidity. 

We know that a current flowing through a wire 
causes what is known as an “ electro-magnetic field ” 








Electrical Things to Make 


ii 


to surround the 
wire, the lines of 
force spreading 
out in all direc¬ 
tions. W h e n 
the current is 
decreased the 
lines of force 
of the electro¬ 
magnetic field 
contract. Now 
you see what 
happens when 
the discharge 
takes place across the gap. 
The electro-magnetic field 
expands and contracts so 
strongly and rapidly that 
waves are formed, very like 
the waves that occur when 
you throw a stone into a 
pond. They radiate out in 
all directions. 


Aerial 


Gap 




1 \ 

d' 

L 

* . 

jf 


Coil 


|i| 1 j u 

i i'll 


Earth 


Fig. 1.—Diagram of an Aerial, 
showing Battery, Coil and 
Spark Gap 


Now I see a question coming. What are the 
waves in ? They are in the “ether.” And what is 
the ether ? It is the name of something, we do not 
know quite what, which pervades all space and all 
matter and can be made to vibrate. We cannot 
handle this ether or look at it or touch it; but 
we know it is there. The electro-magnetic waves, 
then, are set up in the ether, and since the ether 
is everywhere these waves can go anywhere, through 
walls and buildings and up through space. 





























12 Something to Make 

Just as these waves are induced by an electric 
current flowing through wires, so when they strike 
on other wires they can induce current in them. 
By setting up another aerial some distance away 
we can collect a portion of the waves we induced 
and make them show themselves. If we send out 
our original waves in a regular sequence such as a 
long wave, a short wave, and a long wave, then the 
waves we shall collect from our receiving aerial will 
be in just the same order, long, short, long. In this 
way the ordinary telegraphing of “ Morse ” signals 
can be sent and received. 

As I have explained, the waves—Hertzian 
waves they are sometimes called, after the scientist 
Hertz, whose experiments in 1888 were really the 
beginning of “wireless”—go out in all directions. 

This makes wireless telegraphy very useful for 
sending out general messages to a large number of 
stations at the same time ; but, as each station only 
gets a minute portion of the waves that were origin¬ 
ally sent, it makes the picking up of the messages 
rather difficult, especially at a distance. 

This difficulty can be overcome in various ways. 
In Marconi’s original apparatus he used a very deli¬ 
cate instrument which acted as a kind of tap, and 
turned on and off a strong battery current at the 
receiving station which worked his instruments. 
The instrument I am going to tell you how to make 
uses the actual current that is collected from the 
receiving aerial. 

I have explained that the electric “ surges ” in 
the sending aerial are very rapid. Possibly they are 
rushing to and fro a million times a second. They 







Electrical Things to Make 13 

are far too rapid to make a telephone vibrate, also 
they are a lot too weak. What the receiving set 
does is to magnify the very minute and extremely 
rapid surges that are induced in the aerial by the 
Hertzian waves from the sending station. It does 
this first by means of a kind of induction coil and by 
means of condensers. Then the very rapid to-and- 
from vibrations are turned into vibrations all going 
one way—and these can be heard in a telephone 
receiver. This is done by the “ detector.” 

That is all there is to it, and the apparatus is not at 
all difficult to make. Once made, and it will not 
cost much, it should always be in order. There 
are no batteries to replenish or replace. With this 
apparatus you should be able to hear a number of 
the long-distance stations and smaller stations, 
depending on where you are using it. 

You will see that I talk of making a receiving 
set and that I say nothing about sending apparatus. 
The reason is that though you could make a small 
sending and receptor set that would work over a 
dozen yards or so, and would be useful for demon¬ 
strating in a hall, you could not send for any dis¬ 
tance without very expensive apparatus that would 
be very difficult to make and most costly to buy. 
Besides which, you are not allowed, by law, to have 
any sending apparatus that is capable of sending 
messages over any distance without the permission 
of the Postmaster-General, which will only be given 
to professional telegraphists and to qualified scien¬ 
tists for experimental purposes. 

The reason for this is easy to understand. Radio¬ 
telegraphy is now very important, and it would not 






14 Something to Make 

do to have Tom, Dick and Harry sending out waves 
all over the place, blocking real and important 
messages. 

But this need not discourage you. With a real 
long-distance receptor, such as I am about to tell 
you how to make, you can have any amount of amuse¬ 
ment and instruction, and if you set your mind to it 
you may make discoveries and improvements of 
real value to this new and rapidly growing science. 

It is a wonderful experience to sit at your recep¬ 
tor in the evening and hear ships and shore stations 
for hundreds and hundreds of miles in all directions 
talking to one another. And as you gain in experi¬ 
ence there is no reason why you should not add to 
your apparatus so that you can “ listen in ” on the 
wonderful Annapolis station in the United States. 
There is no knowing what you may do until you try. 
Besides which there are now the almost dailv wireless 
telephone broadcasts to be heard. 

If you decide to make this apparatus you should 
apply, as soon as you have started on the work, for 
a licence to put up and use a receptor set. The 
application should be made to the Postmaster-General 
at the General Post Office, London. At the time 
of writing the Postmaster-General states that he is 
not prepared to issue licences of a formal character 
for experimental purposes ; but that he is prepared 
to give permission for the use of reception apparatus 
on certain conditions. One of these conditions is 
that two references from persons of standing, not 
related to the applicant, must be furnished. Another 
is that the applicant must give evidence of his British 
nationality. 






Electrical Things to Make 15 



The conditions as regards the form of apparatus 
are that no valves shall be used without the express 
permission of the Postmaster-General. A “ valve ” 
is an arrangement something like an electric-light 
bulb that is used to amplify signals. There are no 
valves in the apparatus we are going to make, so 
that need not worry you. You must give a descrip¬ 
tion of the apparatus. The following description 
should be all that is necessary: 

1. Loose-coupled tuning inductance. 

2. Sliding tubular condenser (in primary cir¬ 
cuit). 

3. Blocking condenser. 

4. Variable condenser. 

5. Zincite-bornite crystal detector. 

You will have to give a sketch and dimensions 
of the aerial you propose to use. This must not be 
more than 100 ft. high from the ground, nor must 
it be more than 100 ft. long if it is a single wire, nor 



























16 Something to Make 

more than 140 ft. where two or more wires are used. 
This means that if your aerial consists of two wires 
the length of the aerial, between spreaders, must 
not be more that 70 ft. By the way, the length of 
wire allowed includes what is known as the “ leading- 
in wire ”; that is, the wire from the aerial to your 
instrument. Figure 2 shows some possible types 
of aerial, and you should choose the form best suited 
to the space you have at your disposal. If you can 
use either the “ grid ” or “ T ” form you should do 
so. The “ grid ” requires but one post or mast, 
which is a distinct advantage, but the “ T ” form is 
the best of all. We will discuss building the aerial 
later on ; but to enable you to choose your type I 
may tell you that if you propose to attach it to a 
tree, it will be best to fix a short mast firmly to 
the tree top so that the aerial does not meet any 
interference from the branches. 

You will be beginning to wonder when I am 
going to tell you how to set about making your 
apparatus. I know there has been a deal of “ talk,” 
but really it was necessary that we should clear the 
ground by a certain amount of explanation. 

Now we can get ahead. The first thing you 
should make is the “ tuning inductance.” This 
is a single coil of thin wire inside a single coil of 
thicker wire. The thick wire is known as the primary, 
and is connected with the aerial and the earth. 
A tuning condenser is also in circuit with it. When 
the waves from a sending station strike the aerial 
they induce an oscillating current in it, as has been 
explained. The primary coil is so arranged that 
you can switch in a sufficient number of coils or turns 







Electrical Things to Make 17 

of wire to receive these oscillations to the best 
advantage. 

The waves in the primary induce a current in 
the secondary coil. The secondary can also be 
44 tuned ” to take the waves to the best advantage, 
and in circuit with it are a variable condenser, a 
blocking condenser, a 44 detector ” and a telephone 
ear piece. 

To make your tuner or 44 receiving jigger,” as 
it is called, you will require the following parts. The 
cost will depend on what you have already by you. 
In any case this is the most expensive of all the 
parts you have to make. 

2 discs of wood (any good wood) about f in. 
thick, and 4 in. diameter. 

2 discs of wood the same thickness and 5f in. 
diameter. 

2 squares of f-in. teak, 7j in. by 7| in. 

1 piece of teak or other hard wood f in. thick 
and 12 in. by 7J in. 

1 sheet of presspahn ^ hi. thick. Cost 2s. 

4 dozen J-in. round head brass wood screws. 

4 dozen small brass washers to fit them. 

1 dozen countersunk head lj-in. iron screws. 

4 countersunk head iron screws f in. 

1 ft. of ^ in. wide brass strip, springy. 

3 cheese-head metal-thread screws about J in. 
diameter and 1J in. long, with 4 washers and 
3 nuts to each. 

8 oz. No. 28 s.w.G. d.c.c. copper wire (cost 
about 5s.). 

3 oz. No. 36 s.w.G. d.c.c. copper wire (cost 
about 4s.). 

B 







18 Something to Make 

A quantity of small tacks about | in. long. 

About a gill of shellac varnish. 

The wood and screws, etc., you can obtain from 
local shops, if you haven’t them already. The press- 
palm and wire you should get from an electrical 
apparatus dealer. 

The tuning inductance or tuning “ jigger ” is the 
most difficult thing you have to make, and, therefore, 
in accordance with my usual plan, I am advising 
you to make it first. First of all you must bore 
holes in the 4 in. discs. If you cut them yourself or 
have them cut for you the holes should be made at 
the same time. In the centre of one the hole should 
be £ in. diameter, and in the centre of the other 
J in. diameter. Now you must cut from your sheet 
of presspahn a piece 9 in. wide and 1 ft. lj in. long. 
Get the dimensions exactly right and save yourself 
trouble. Mark it out on the surface of this fibre 
stuff with pencil, and cut with a sharp knife. With 
the presspahn and your two wood discs you must 
make a cylinder 9 in. long. To do this tack one 
end of the stuff to the discs and then coat the edges 
of the discs with strong fish glue. Now tack down 
the edges of the presspahn first on one side and then 
on the other to the discs until you have your cylinder. 
You must be careful not to crack or damage the 
presspahn. You will find that you have a lap of 
about f in. of the presspahn. Tack it down to the wood 
after you have given it a coat of glue along its length 
so that it will stick. You may find that to make it 
stick without buckling in the middle you will have 
to fasten it, temporarily, with string. 

This is the secondary coil you are making, the 









Electrical Things to Make 19 

one with the thinnest wire, and when it is dry you 
are ready to wind on the wire. To do this you 
need a lathe or some sort of winding apparatus. 
The one described in my article of “ X-Ray 
Apparatus ” (see page 77) will do very well. Or 
you can fix your cylinder up as shown in Fig. 3. 
To do this you want a piece of wood rod or metal 
tubing about 2 ft. long. Pass it through the f in. 
hole and push it up against the J in. hole. If you 
have a tube you must previously have plugged the 



end with wood. Insert a screw into the rod or plug 
through the J in. hole so that the cylinder will 
revolve without wobbling. A cotton reel loosely 
screwed on to the disc will make a handle. Hold the 
end of the rod or tube to your bench or table with a 
vice or clamps, and you are ready to begin winding. 

Mark the surface of the cylinder off into 12 
equal spaces. The actual space you have to divide 
up is not the clear 9 in., because you do not com¬ 
pletely cover the cylinder from end to end. It is 
the space between the tacks. This should be about 
8 in. and, if it is, the spaces you will mark off will be 




























20 Something to Make 

just about | in. each. These markings are shown 
on Fig. 3. Now you want your No. 36 wire. This 
is very thin and easy to break, so handle it care¬ 
fully. Secure one end with a small brass screw to 
the disc farthest from your temporary handle, leaving 
a free end of about a foot and a half of wire. Now, 
turning the handle in the same direction as the hands 
of a clock move, wind on your wire, very smoothly 
and evenly, keeping it under slight tension the whole 
time. A friend to help in this operation is very use¬ 
ful. The wire coils must 
touch each other all the 
way along. When you 
reach each mark on the 
cylinder—there are, as 
you see, eleven of them 
—make a loop of about 
1 ft. 3 in., measured 
double. That is you 
will have 2 ft. 6 in. 
of free wire. Secure it 
with a twist close to the coil and continue winding 
until you reach the next mark. In Fig. 4 the coil 
is shown finished, with the “ tappings ” standing 
out. To make a good and convenient job you 
should not have these tappings straight along as 
shown, but each should be a little farther round the 
coil than the next, so that they occupy about one 
third of the circumference. Finish the winding and 
fasten off the wire with another small brass screw. 
Leave about a foot and a half of free end. 

Before you take the coil off the winding apparatus 
give it a good coating of shellac varnish and let it dry. 



Fig. 4.—View of Secondary Coil 
showing “ Tappings,” after 
Winding 




















































































































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22 Something to Make 


Whilst it is drying you can start on making the 
end board ready for the contact studs and tuning 
switches. 

For this board you need one of your 7J in. square 
pieces of teak or hard wood. Draw two diagonals 
to mark the exact centre. Draw, with a pair of 
compasses, from this centre, two circles, one of 5| in. 
and another of 4J in. These show where the primary 
and secondary coils will come. Now look carefully 
at Fig. 5, and you will see what next you must do. 
Draw a straight line down the centre of the board, 
and on it mark off three new centres, shown as a, 
b and c on the figure. Centre a is | in. above 
the centre of the board. From it describe a circle 
with a radius of 2f in. (the radius is the width of the 
compass legs apart). You need only draw two- 

thirds of the complete circle in the top half of the 

board, as shown in Fig. 5. Centre b is § in. 
below the centre of the board. From it describe 
a half circle in the lower part of the board, having a 
radius of 2J in. Now divide the upper circle into 
thirty equal divisions and the lower circle into 

twelve equal divisions. The upper circle is for the 

primary studs and the lower circle for the secondary 
studs. 

All this sounds rather complicated, but it is really 
quite simple. Now drill J in. holes through centres 
A, b and c. Centre c is f in. below the centre 
of the board. Drill holes of the same diameter at 
the points marked s in the diagram, where the 
screws go through to secure the coils to the board, 
also holes—same diameter—for the four terminals, 
two marked e and a on top of the board and 









Electrical Things to Make 23 

two in the bottom right hand corner. Drill also a 
J in. hole for the “ tubular condenser ” where 
shown in the bottom left hand corner of the board. 

Now you can proceed to put in the round-headed 
brass contact screws or studs. There are SI on the 
primary stud circle and 13 on the lower or secondary 
stud circle. Put a washer under the head of each 
and do not screw them up quite tight. Leave room 
to place a wire under each. This done you must 
bore fine holes against each of the studs, to allow 
the wires from the coils to come through from the 
back. The very small dots on Fig. 5 will give you 
an idea where to place these holes. Obviously they 
must be in such a position that they are not blocked 
up when the coils are in place and screwed on to the 
back of the block. 

The next thing to do is to fix one of your 5f in. 
wood discs to the block through the screw holes s, 
taking great care to get it exactly central with the 
centre of the block. This must be done before you 
drill the holes against the secondary studs, for they 
have to go right through the block and the disc. 
Whilst the disc is screwed to the block, mark the 
places where the holes through centres a, b and c 
come and make recesses in the disc to take the heads 
of the tuning switch screws and wires leading from 
them. Before you take the block and the disc apart 
mark them so that you can fit them together in 
exactly the same position again. 

Now look at Fig. 6 and make your switches. 
These are formed of your strips of springy brass. 
These strips must be a bit longer than the radius of 
the circles they have to cover for they have to be 











Something to Make 


24 

shaped and allowance must be made for boring. 
Details of the switches are shown in Fig. 6. To fix 
the springs, for which you must make handles as 
shown, and secure them by screws, you need the 
three cheese-headed screws with the nuts and washers 
mentioned in the list of parts. Pass the screws, 
on to which you have threaded washers, through 
the board in their proper places. Between the screw r 
head and the washer wrap the cleaned end of a one 
and a half foot length of insulated wire. Then, on 
the other side of the board, the front side on which 
are the contact screw heads, screw down a nut on to 
each switch screw, fixing it firmly. On these mount 
the switches to their proper heights, as shown in the 
diagram. You may have to pack up the highest 
secondary switch with little washers cut out of 
waste bits of presspahn. When this is done to your 
satisfaction, screw in four brass screws, small ones, 
at the places marked w on Fig. 5 to act as stops, 
and you have finished with your fronthead board 
for the moment. 

You should now turn your attention to the wind¬ 
ing of the primary coil. Having already wound 
your secondary you will know how to proceed with¬ 
out much further explanation. The disc in which 
you have drilled the small holes should have a f in. 
hole through the centre. This has to be fixed with 
small screws to the end of the Secondary Coil, which 
also has a § in. hole. Before you do this you must 
thread through the holes the wire tappings from the 
secondary coil in order, starting with the free end 
from the far end and then the first end tapping, 
which you pass through the right-hand hole. You 








_ Electrical Things to Make 25 

end off with the near free end. This is shown in 
Fig. 7. So that there is no possibility of subsequent 
mistake you should tie a piece of red worsted or tape 
to the first tapping. Now fasten the primary disc 
to the secondary discs and tie all the tappings together 
to keep them tidy and out of danger of being dragged 
away. The other 5f in. disc should be fastened to 
the other end of the secondary coil. It should have 
a hole drilled in it to take the screw if you are using 
the winding apparatus shown in Fig. 3. 

A piece of presspahn forms the cylinder. It 
should be of the right dimensions to go on properly. 
This will probably be 10J in. by 1 ft. 7 in. Secure 
it with glue and tacks just as before. Coat it with 
shellac varnish and then wind on your No. 28 wire. 
The procedure as regards the tapping is not quite 
the same as for the secondary. You must wind on 
ten turns, having secured the loose end with its one 
and a half foot free portion as before, and then make 
a tap of the same size, or thereabouts, as you made 
your secondary taps. Wind on another ten turns, 
and then a tap and then another ten turns and a tap. 
(You are of course winding in the same direction as 
you wound the secondary.) This will give you 
three taps. Now divide your remaining space on 
the cylinder into a sufficient number of equal spaces 
to give you 27 more tappings. That means that you 
must divide your space into 28, the last space ending 
against the tacks where your other free end will be. 
When you have finished winding and have made all 
your tappings as directed, securing each with a turn 
close to the coil as I told you when you were winding 
the secondary, you must give the coil a thorough 









26 Something to Make 

coating with shellac varnish. When it is dry turn 
all the tappings away from the end where the second¬ 
ary tappings are and tie them up. You now have 
your primary coil surrounding your secondary coil. 

But little remains to be done to complete the 
coils. Take the end board which you have pre¬ 
pared with its studs and switches, and pass through 
the holes you have bored for them the tap wires 
from the secondary coil. Treat them gently, and 
when they are all through a couple of inches, begin to 
shift them farther and farther through, one at a 
time, until you have the block square on the coil 
end. The best way to do this is to stand the coil 
on its end with the secondary wires uppermost. 
You must work very carefully. Start with the far¬ 
thest free end in the right hand pole, and then the 
first tapping and thread them through in order. If 
you have put them through the primary coil end in 
the right order you cannot make any mistake. 
When this is done fix the block to the coil with the 
three screws you used to fasten the two together 
when you were boring the holes. Now you must 
very carefully remove the insulating material from 
each tap wire and the two end wires close to the 
studs and place them under their respective screw 
heads, tightening up the screws on them. Gently 
does it, for you don’t want to break the wires and 
cause yourself endless trouble. Remember that the 
secondary coil wire is very delicate and that the 
secondary is now completely covered in. If you 
break one of the wires inside you have all your work 
to do over again. 

Now thread through the primary wires, looking 







Electrical Things to Make 27 

at Fig. 7 again. You will see that you don’t start 
with the free end in this case ; but with the first 
loop. Also you start on the left hand, not on the 
right. When you reach the last stud you will find 
that your near free end comes through the hole next 
to it. Connect the loops or taps to the studs as 
directed for the secondary. 

In the holes marked e and a on Fig. 5, fix two 
large terminals of the type provided with nuts on 
the fixing screw. Before you tighten up the nuts, 
fix to the one marked e the first free end of the 
primary coil, which is still doing nothing. You 
will remember that you have fixed some loose wires 
to the switch screws. Lead the one coming from 
screw marked A in Fig. 5 to the terminal marked a, 
and fix the bared end under the washer or nut before 
tightening it up. Now attach with screws the other 
piece of 7\ in. square hardwood to the other end of 
the coil, so that it is square with the switch block 
and the coil is complete. 

The Tubular Condenser should cost you some¬ 
where between a shilling and eighteenpence to 
make. You must have a piece of thin brass tube 
13 in. long and £ in. diameter inside, a piece of thin 
brass tube 7 in. long and f in. outside diameter, 3 
round-head brass wood-screws \ in. long, about 
3 yds. of sticky tape, such as used by electricians 
and motor-cyclists, a brass washer f in. diameter, 
a 2-ft. length of insulated flexible wire and a small 
wooden knob or handle. 

If you look at the diagram (Fig. 8) you will see 
where the tubular condenser has to go. Your 13 in. 
piece of tubing is too long to fit in between the ends 








28 Something to Make 

of the coil blocks. Mark it off so that you have a 
little to spare at each end of the tube, and then cut 
it with a saw, leaving one piece at one end and two 
pieces at the other that you can bend back to form 
lugs, as shown in Fig. 8. These lugs must be finished 
off nicely and bored to take the brass screws. Now 
cut away the tube for half its diameter to three inches 
from the “ one lug ” end, and then fix the tube in 
position so that the “ two lug ” end comes opposite 
the -f in. hole you bored in the switch block. Use 
the brass screws to secure it through the lugs. 

Now secure your flexible wire to one end of your 
remaining length of brass tube. You can either 
bore a hole about J in. from the end to do this, or 
you can plug the end with wood or metal to secure 
a good contact. Wrap the short length of tube care¬ 
fully with the sticky tape so that it will slide nicely 
in and out of the bigger tube, plug the other end 
with wood and screw on to it your handle with the 
brass washer, so that the short tube cannot pass 
right into the big tube. Now pass the flexible wire 
into the tube so that it comes out through the 
portion of the big tube you have cut away, draw 
it through carefully and the small tube will follow it, 
until the brass washer on its other end stops it. 
Connect up the inner tube by means of the flexible 
wire to the a terminal, and connect up the outer 
tube with a short bit of proper insulated wire to the 
E terminal. And that’s that! 

I don’t think you need anything more than the 
diagram which appears as Fig. 9 to enable you to make 
the blocking condenser. You must cut from thin sheet 
zinc (one square foot will be enough) seven sheets 










Screw 


Cover 



«Pre3Spahn. 
= Zincs. 


Fig. 9.—Detailed View of Blocking Condenser 


of the dimensions shown at a in the figure. Put 
them together interleaved with sheets of presspahn 
sufficiently large to project out all round them. 
Four tabs are connected on one side and three 
on the other. The tabs should be drilled with a hole 
when they are soldered together. It improves the 
working of the condenser if the presspahn and the 
zincs are coated on each side with shellac varnish. 
The base and cover are formed of thin pieces of hard¬ 
wood. The base is fixed to the cover by two screws 
as shown, and the base should be fixed to the 12 in. 
by in. piece of teak or hardwood which forms 
the cover of the coils. 

For the variable condenser you must have a 
square foot of J in. teak or other hardwood, 1 square 
foot of thin sheet zinc, 2 small brass nuts and bolts 
about J in. diameter and | in. long, 2 small brass 
terminals, 6 old J-plate negatives, 8-in. flexible wire 
and a handle off a small screwdriver. 




































30 


Something to Make_ 

First of all cut, or get someone to cut for you, 
your old negatives into two pieces each measuring 
in. by 3J in. Then cut "from the sheet zinc nine 



Fig. 10.—Zinc required for Variable Condenser 


pieces shaped and dimensioned as shown in Fig. 10. 
The length of the zinc without the tab is 3 in. 
This done, you should make the box to hold the 
glasses and zincs. It is fashioned from the J in. 
thick hardwood. From Fig. 11 you will see that 
the tabs are arranged at the top at both ends of the 
box. To the moving end of the box, the one with 
the handle to it, four zincs are fixed, by means of 
saw cuts in the wood into which the tabs fit firmty. 
The fixed end of the box has five zincs fixed to it in 
the same way. Before you make your box you must 
pile your glasses and zincs together, first a glass and then 
a fixed zinc and then a glass and a moving zinc, until 
you have disposed of all your zincs and ended with 
another piece of glass. When you are finally fitting 
the condenser together paint the glasses with shellac 
varnish on the sides that are in contact with the 
fixed zincs, taking care that none of the varnish 
exudes on to the other side. This will hold the 



















Electrical Things to Make 31 

glasses in place. When you have fitted the condenser 
together, bend the ends of the tabs four at one end 
and five at the other, and drill them and fix them 
together with the little brass bolts and nuts. 

The base of the box must be rather wider than 
the box so as to take two terminals and the screws 
for fixing it to the cover of the coil. As you will see 
from the diagram, Fig. 11, the moving end slides 
on the top of the coil case itself. The tabs of zinc 
at that end are connected to the terminal nearest 
to it. The tabs of the fixed zincs are connected to 
the other terminal with an ordinary piece of insulation 
wire. That done you can screw it to the coil top. 

You can quite easily buy now an excellent silicon 
and gold point detector for 8s. 6d.; the zincite- 
bornite detector which I have specified in this set 
of apparatus will cost you at least 6s. to make, 
besides your time. It’s up to you to decide whether 
you will make it or buy it. At any rate I will tell 
you how to make it and then you can please yourself. 
It is the last thing you have to make, and, having 
got so far you may as well do the whole thing. The 
details are shown in Fig. 12. The base, called a 
“ pattress ” in the diagram, is 4 in. square and made 



a b 


Fig. 11.—Variable Condenser 










































32 


Something to Make 


of wood. It can either be a shallow box or solid 
with holes sunk to take the necessary nuts and bolts. 
The pillar is made of a piece of ebonite tubing or 
rod f in. diameter and l£ in. long. If it is rod it 
must be drilled. Wood will do for this pillar, or 
glass tube. It could be made of brass tube. The 
long portion of the pillar is 1 in. long, and the short 

top piece is 
sawn off it to 
make a piece 
£ in. long. A 
piece of 
springy brass 
is used to 
make the long 
arm that holds 
the upper 
crystal. As 
you will see 
from the dia- 



Coil Cover 

Fig. 12.—Detailed Diagram showing Zincite- 
bornite Detector 


gram there is a short arm attached to the spring 
to which the crystal cup is attached. I have not 
given exact dimensions because the proportions 
will depend on what stuff you have to use. The 
sketch shows this arm made out of a portion of 
an old electric light ceiling rose, which has a small 
set screw in the side. Both upper and lower crystal 
cups are made out of an old *303 military cartridge 
case. Such a thing can be found in almost any house 
since the war. The portion of the old ceiling rose 
is likely to be your difficulty. There must be a short 
arm at the end of the spring that can be moved through 
a small radius, so that all parts of both crystals can 



















Electrical Things to Make 33 

be used, and if you cannot obtain the old part of the 
ceiling rose I should suggest that you do the next best 
thing, purchase one or two crystal cups at the cost 
of lOd. or Is. each. If you only get one use it for 
the upper cup and bolt it, with the nut and bolt 
provided with it, to a short metal arm that you can 
move about on a nut and bolt attachment to the 
spring. 

The adjusting screw works in a piece of J in. 
hard brass strip, and the hole for the screw must be 
tapped to take the thread. The knurled head of 
the adjusting screw can be made of wood or ebonite, 
or from an old beer-bottle stopper. An adjusting 
screw complete with knurled head of ebonite would 
cost you Is. to buy, and you might have a difficulty in 
getting your brass arm tapped to fit it. The pillar 
with the spring and brass arm are bolted to the base 
with a 2 in. metal thread screw with a nut and 
washer top and bottom. 

The crystals must be bought. Zincite, which goes 
in the upper cup, will cost you 2s. 6d., and the 
bornite, which goes in the lower cup, costs Is. If 
you use portions of an old cartridge case for your 
holders you will have to fill the base of each with 
molten solder and press the crystals down on it. 
By buying proper cups you fix the crystals in with 
three set screws, and you can shift the crystals about 
so that you can use all the surface. 

To finish off the detector fix two small terminals 
to the base. The screw-in pattern will do. Con¬ 
nect one to the bolt securing the pillar and the other 
to the bolt securing the lower crystal cup. You 
should cover the detector with a glass of some kind 


c 







34 


Something to Make 


to protect the crystals from dust. The diagram 
shows this cover made of an old glass tumbler. One 
of the reasons why I have not given very precise 
dimensions for your detector is that you should make 
it to go inside any cover you have available. 

You can now complete your apparatus by fixing 
the detector to the coil cover. There is nothing 
more to do except to make a case to take the whole 
apparatus. This should have a door in front so 
that the switches, etc., can be got at, and it is as 
well to make it with a hinged top. You can please 
yourself about the case. If you don’t make it keep 
your set in a box when not in use. 

Of course, you are all impatience to try your set. 
If there is a friend of yours who has an aerial or any 
wireless experimenter in your neighbourhood you 
will easily get permission to try out your apparatus 



on his aerial. Wireless 
users are very friendly to 
anyone else who is in¬ 
terested in the same 
hobby. However, I will 
presume that you are all 
on your own and that 
you cannot do anything 
until you have put up 
your aerial. 


By the way, there is 
still something else neces- 


Soldered Join pjg 13 



sary to complete 
your apparatus. 
That is a tele¬ 
phone ear - piece. 











Electrical Things to Make 35 

You cannot possibly make this for yourself, unless 
you are a very skilled electrical worker, so I am 
not going to bore you with descriptions of what 
you cannot do. You must buy your telephone. 

What you buy will depend on what you can 
afford. You can get a single ear-piece for 10s. 6d., 
but what I recommend is a 14 C.Q. ” double 
set at 32s. Gd. This has two ear-pieces each wound 
to 1,000 ohms resistance, and a double adjustable 
head band to keep the ear-pieces in position. It is 
a thoroughly businesslike bit of apparatus and gives 
excellent results with this set. 

Now for the aerial. Look at Fig. 2 again. You 
have already made up your mind as to the form you 
are going to use. Remember that you mustn’t use 
more than 100 ft. of wire for a single aerial including 
“ lead-in,” nor more than 140 ft. of wire for a double 
aerial, including lead-in. The same rule applies for 
triple and quadruple wires. You must not have 
any portion of your aerial more than 100 ft. from 
the ground. You should, however, endeavour to 
get a good portion of it at least 30 ft. above the 
ground and well clear of high buildings and 
chimneys. 

The wire should be either copper, not smaller 
than about 14 s.w.G., or aluminium, or one of the 
special wires like silicon bronze. On no account 
use iron wire as it is not effective. Aluminium will 
probably prove far too costly. Copper wire will be 
the cheapest; but I believe very good results are 
to be got from silicon bronze, which costs 10s. for 
100 ft. plain and about 17s. Gd. braided. If you are 
fitting up a double wire “ T ” aerial you will need 









36 Something to Make 

four insulators. The 3j oz. “ Shell ” type are ex¬ 
cellent for a small aerial and cost Is. 6d. each. Fig. 13 
shows you the details of fixing your wires to the 
spreaders. If you know how to splice braided wire 
and use that kind, splice all your joins. If not make 
a good twisted joint in each place and solder it. 
Fig. 13 shows also the details of joining the “ lead- 
in ” to the aerial. 

You still have one or two connexions to make 
in your apparatus. The telephone head-piece is 
connected to the two lower right hand corner ter¬ 
minals on the switch board. The upper of these 
two terminals must be connected to the secondary 
switch marked c in Fig. 5, also to one terminal of 
both the blocking and variable condensers. The 
b secondary switch in the same figure should be 
connected, of course with insulated wire, to the lower 
crystal of the detector. Connect it also with that 
terminal of the variable condenser that has no 
wire attached to it. Now you must connect the 
upper crystal of the detector to the unoccupied 
terminal of the blocking condenser and from this 
terminal join up with the lower telephone terminal. 
Fig. 14 will help you to understand this. 

Connect up the e terminal to one of the water 
pipes of your house, or to a copper plate three or 
four feet square buried several feet deep in moist 
earth. Connect the a terminal to the aerial lead-in 
and you are all ready to “ listen-in ” on the signals 
that are being sent for many hundreds of miles 
around you. 

The night time is the best for making a start, for 
signals are clearer then and many important stations 








Electrical Things to Make 37 


send at night, with well-known wave-lengths at stated 
times. 

Fig. 15 shows you the correct position for the 
aerial or primary tuning switch to take signals from 
various well-known stations. Start by trying to 
find one of the well-known stations. 

It will be perhaps as well to try out your detector 
before you actually begin “ fishing ” into space for 
signals. Get a small induction coil or electric bell, 
with the gong removed, and place it about 2 ft. from 
the coils. Connect up with a battery and bell push 
and keep on screwing the upper crystal of the detector 
down on to the lower one until, on working the coil 
or bell with the push, you get the loudest “ buzz 55 
in the telephone. This tells you that the detector 
is set about right. 

Draw out both tubular and variable condensers 
until they are as far out as they will come without 
being actually removed. We will suppose that it is 
nearly 8 o’clock p.m., and you are going to try for 


PRIMARY 


SECONDARY 



Fig. 14.—The Finished Diagram, showing all the Connexions of a 

Wireless Receiving Apparatus 























38 Something to Make 

Paris. Place your primary switch on the eighth 
stud from the left. The lower secondary switch 
should be on the end stud on the right hand side, 
and the upper secondary switch on the fifth stud 
from the right hand side. At 8 o’clock, to the tick, 
you should hear the distinctive note of the Eiffel 
Tower signals. Move the primary switch between 
the sixth and ninth studs until you are getting the 
best results. Then move both secondary switches 
towards the left, one stud at a time. When the 
upper secondary switch is at the extreme left hand 
try tuning the primary again. You can also push 
in the variable condenser a bit and note the effect. 
It should make the signals loud again. 

Cleethorpes works at 8.30 p.m. The position of the 
primary is shown in Fig. 15. Lower secondary switch 
as for starting on Paris and upper secondary on 
fifth or sixth stud from right. You can try for 
Cleethorpes again at 9 p.m. and 10 p.m. Paris comes 
on again at 10.30 and at 11.30 you can have your 
big try of the night, for the great station at Poldhu 
begins then to send out its news to the ships at sea, 
with short intervals each fifteen minutes. It con¬ 
tinues until 1.30 in the morning, and by that time 
you will have had quite enough for one night. To 
get Poldhu place the primary switch one or two 
studs lower than for Cleethorpes, lower secondary 
switch should be on end stud, right hand side, and 
upper secondary on fifth or sixth stud from right. 
Proceed with your tuning as before. 

Paris has a 1,900 metre wave-length, Cleethorpes 
a 4,000 metre wave and Poldhu a 3,000 metre wave¬ 
length. Sea-coast stations and ships use wave-lengths 




Electrical Things to Make 39 

from 300 to 600 metres, and to tune in for them you 
should have the primary switch on the first or second 
stud on the left. The secondary switches should be 
on the first and third studs on the right or on the 
eleventh and thirteenth. 

When trying for Clifden with its 7,200 metre 
wave-length, the primary should be as shown on 
Fig. 15, and all the secondary coil in circuit, which 
is got by having the secondary switches at opposite 
ends of their studs. The variable condenser should 

Cl eethorpee —' 



be about half in. The position is also about right 
for telephone reception, depending, of course, on the 
wave-length. 

Of course, you must learn the Morse alphabet of 
dots and dashes if you are going to read the signals, 
and there isn’t much fun in listening to what you 
can’t understand. It is not difficult to pick up; I 
dare say many of my readers have been scouts and 
have already learned it. 

I have only one thing to add now. Don’t be 






40 Something to Make 

disappointed it you have difficulties in tuning in at 
first. Practice will make perfect, and once you 
have heard some signals you will speedily become 
adept in getting them to sing out to you with a good 
clear note. Try and try, and keep on trying until 
you can pick up the signals I have mentioned at once, 
without any trouble. By then you will be in a fair 
way to becoming an expert receiver. I wish you 
the very best of luck. 









HOW TO MAKE AN ELECTRIC 
* MACHINE 


A WIMSHURST Influence or High Tension Electric 
Machine is a very useful and interesting piece 
of apparatus for any fellow to have who goes in 
for electricity as a hobby. With it you can do 
almost anything that can be done with an induc¬ 
tion coil, and it has the merit of being much cheaper 
and much more easy to make. A Wimshurst 
machine will work small X-ray tubes, illuminate 
vacuum tubes, provide disruptive discharges, charge 
Leyden jars and can be used for all purposes and 
experiments which require high tension or static 
electricity. As to how it works—well, we will leave 
that until you have made it, or at least until you 
have read how it can be made. Then it will be 
easier to explain, for though these machines are 
simple to make and work, they are not very easy 
to understand, unless you are well up in electricity. 
The only crab about them is that they are very much 
influenced by the state of the atmosphere. The one 
I am going to tell you how to make will give a 
4-in. spark when the air is dry and the machine 
is free from damp and dust, but on a wet and rainy 
day it behaves like a sulky kid, unless it is warmed 
and dried, when it works as well as ever again. 

Fig. 1 will show you what the machine is like 
when it is finished. It is known as a “12-in. 
plate ” machine, because that is the diameter of the 
two glass plates that are the most important part of 

4i 


42 Something to Make 

the machine. There are a few small differences 
between the one shown and the one I am going to 
tell you how to make ; but they are only in the re¬ 
placing of some of the metal work by wood, which 
is cheaper and more easy for the amateur to work 
with. 

The first things to make are two glass plates. 
I have told you before that it is always wise to tackle 
the most difficult or the longest job first, because 
when that is done, you have “ broken the back ” of 
the job, and before you know where you are it is 
finished, and you have the pleasure of seeing your 
apparatus at work, which is what you are longing for 
all the time you are making it. Let us get on with 
the plates then. They are made of clear, white 
plate glass, 12 in. in diameter, with a hole about 
\ in. diameter exactly in the centre. If you can cut 
these yourself, by all means do so ; but you will 
probably find it a better plan to get them cut by your 
local glass merchant. If you want to be certain that 
you are getting exactly the right thing, you can spend 
11s. and get a pair of first-class plates of tested glass 
from Messrs. Scientific Appliances, 11 and 29 
Sicilian Avenue, London, W.C.l. This firm, which 
gives special attention to the wants of our readers, 
can supply you with tin-foil and brass balls and any¬ 
thing you cannot make yourself. IIow much you 
will have to buy depends on whether you are used to 
making models and have about the place short lengths 
of brass tube and rod and things like that. 

Having obtained your plates, clean and dry them 
carefully, and then coat them all over on each side 
with shellac varnish. A bottle of this varnish, costing 










Electrical Things to Make 43 

ninepence or a shilling, will be ample for all you require 
on this job, and should leave some over for something 
else. Shellac varnish is always useful when you are 
doing electrical work. When the varnish is quite 
dry proceed to lay out the work as I have shown in 
Fig. 2. On a sheet of paper—any clean piece will 
do — draw a circle 12 in. in diameter. Inside 
this draw another circle 11 \ in. in diameter and 
another 7 in. in diameter. Now proceed to divide 
your circles up with straight lines across the centre. 
This is all done with the compasses, and I have shown 
the method by means of dotted lines. Draw the lines 
thick so that they will show up through the varnished 
glass. 

Now cut a piece of cardboard to the shape and 
dimensions I have shown in Fig. 3. Using this as 
a guide, cut out 24 pieces of tinfoil and stick them on 
to the glass as I have shown in black on Fig. 2. 
Take care to get them firmly on to the glass with no 
air bubbles underneath and no loose edges. These 
are known as the sectors and are the essential part 
of the machine, from which the electricity is gener¬ 
ated to give the sparks. By doing the work over the 
lines you have drawn you will be sure to get the 
sectors rightlv spaced and in the right position. In 
Fig. 2 I have shown seven of them in position. 
When you have put twenty-four sectors on one sheet 
of glass, lay it aside to dry, place the other glass 
plate on your drawing, cut out another twenty-four 
sectors and proceed as before. When that is done, 
the hardest part of the job is over. When the plates 
are dry, wrap them up carefully and put them away. 
You don’t want to get them cracked or broken. 






44 


Something to Make 


Now you can tackle an easy task in making the 
base-board. Any piece of good wood § in. thick will 
do for this. The front measurement is 15 J in. and 
the side 9J in. The hole is 5 in. by 4j in., and the 
front edge of it comes 1 in. from the front edge of 
the board. By screws, fix to each end of the board 
two supports made of wood about 11J in. long, 
1 in. deep and 2 in. thick. You will see how these 
go by looking at Fig. 1. They are only supports, 
and you can make them any way you like, provided 
they are firm. On Fig. 4 I have shown some of the 
parts of the machine in position. This is as a guide 
for you later on. 

Whilst you are at work on wood and have your 
tools out, you had better make the two supports for 
the plates. One of these is shown in Fig. 5, but they 
are^both exactly the same. The actual shape does 



Fig. 1 


not matter. The 
important things 
are that the 
bottom should fit 
nicely into the 
hole in bottom 
board, and so it 
must be 4J in. 
across, and that 
the centre of the 
hole should be 
exactly 8 in. above 
the bottom board 
of the machine. 
This hole is to 
take the spindle 












Electrical Things to Make 45 



on which the plates 
revolve. I have 
shown the hole 
bushed with a piece 
of metal tube, and 
the two little black 
squares indicate keys 
that keep the bush 
from turning in the 
wood. If you make 
your bush a driving 
fit in the wood you 
can dispense with 
one of the keys, but *' Fig. 2 

you should fit the one 

that holds the spindle into the bush. If you like you 
can do without the bush altogether, because the spindle 
is fixed and does not revolve. All you have to make 
sure of here is that the spindle will not turn. I will 
explain why later on. In my drawing of the bottom 
board—Fig. 4—I have allowed for the side supports 
being made of f-in. wood. You will find this a con¬ 
venient thickness, as it allows of the supports being 
rigid, and not giving. If you are a sufficiently good 
carpenter you can devise a way of grooving the sup¬ 
ports into the bottom board. I have made it as 
simple as I can, and all you will want to fix the sup¬ 
ports in place is three long screws, about 1^ in. long 
and not thick ones. If you can countersink the heads 
so much the better. 

The lower hole in the supports comes If in. above 
the bottom board. This is to take the moving spindle, 
to which the wheels are fixed that revolve the glass 













46 Something to Make 





vV< 


Fig. 3 



plates. This hole should be bushed or it will soon 
wear and cause trouble. Make the bush of a small 
piece of brass tube sufficiently large to fit over your 
spindle without any wobble. You can choose the 
dimensions of your spindle and bushing according to 
the stuff you have in hand or can easily obtain. 

Now you want a lathe, or a friend with one. If 
you have no lathe and no friend who can do the work 
for you or allow you to do it, you will have to solicit 
the aid of the local turner or woodworker. You 
must now prepare the two wooden hubs to carry the 
glass plates and the two wooden wheels. In Fig. 1 
the wheels are shown made of wood. Aluminium 
wheels are very nice, but they cost five or six shillings 
a pair, and you can make wooden ones for a few pence. 

The bosses are shown in Fig. 6. The groove 
that takes the driving band is 1 in. in diameter. 
The curved end of the hub is lj in. in diameter, and 
the flat end is 2 in. in diameter. From the fiat big side 
that comes against the glass and is fixed to it, to 
the curved end that comes against the support is 
If in. Both these hubs must be bushed with brass 











































Electrical Things to Make 47 


tube of the right diameter to take the spindle on 
which they revolve. Don’t forget that the spindle 
goes right across the machine from side to side, as 
I have shown in Fig. 4 ; it is marked s. The bushings 
for the hubs must project a little from the flat end, 
for they go through their respective glass plates and 
are separated from one another by a leather washer. 
You should fit the bushings and adjust their length 
when you assemble the various parts. 

The wheels are shown in Figs. 7 and 8. They are 
4j in. in diameter, and \ in. thick. The groove is 
J in. deep and T 3 g in. across at its narrowest part. 
Finish them off nicely, particularly the grooves, and 










































4 8 Something to Make 

provide a means of keying them on to the axle as I 
have shown in the drawings. 

Now you must make two posts, or rods, some¬ 
where between j in. and 1 in. round. They are to 
support the collecting brush holders. On Fig. 4 I 
have shown the position for one marked a. The other 
is shown with the collecting brush holder in position 
on top of it. They can either be made of wood, 
ebonite, or glass rod or tube. Wood is the easiest 
to work with as you can drill out holes in the bottom 
board to fix them in. If they are made of ebonite 
or glass you will have to turn up little shoes of metal 
or wood to secure them to the base-board. The 
columns shown in Fig. 1 are held in this way. What¬ 
ever material you choose to make them of—you must 
not use metal—the height must be such that the col¬ 
lecting brush holders come exactly half-way up the 
glass plates. If you are sticking to the dimensions 
I am giving you, you will find that this will necessitate 
the rods being 8 in. above the bottom board, measured 
from the bottom board to the top of the rod, when in 
position. The rods or posts are fixed to the bottom 
board so that their centres are 3j in. from the respec¬ 
tive sides of the bottom board and 3J in. from the 
back edge. 

Now you should make the Leyden jars or con¬ 
densers. There are a pair of them, and Fig. 9 will 
show you what they are like. The machine will work 
perfectly well without them, and indeed for some 
purposes it serves better without the jars than with 
them. The effect of the Leyden jars is to make the 
sparks much fatter, brighter and more powerful, 
but less frequent. The jars are made of glass. In 






Electrical Things to Make 49 

my drawing—Fig. 9—I have shown the best form for 
simplicity of handling. This is a glass jar 5b in. tall 
and lj in. in diameter. On Fig. 4 I have shown by 
the circle marked l where the Leyden jars are to be 
fitted. You may find it convenient to use some other 
form of jar or bottle. You must remember in select¬ 
ing your bottles that they should have their mouths 
sufficiently large to enable you to coat the interior 
of the glass with tinfoil. The bottles should be 
coated inside and out with shellac varnish. When 
this is dry and you have ascertained that the glass 
is completely covered, varnish the inside again to 
about half-way up or a little over. Then cover this 
painted portion and the bottom of the bottle with 
tinfoil, laying it on smoothly and taking care that 
there are no air bubbles under the foil nor any holes 
in it. Then coat the outside of the bottles and their 
bottoms in the same way, making the outside covering 
the same height as that inside. When they are dry, 
place a few pieces of crumpled-up tin-foil in the bottom 
of each jar. This is to ensure contact between the 
rod and the foil lining. 

Now you should make the corks for the jars. 
These are best provided with wooden tops as shown 
in Fig. 9. The cork is easily fixed to the wood with 
glue. Through the centre of the stoppers you should 
drill a small hole, but you can leave this until you 
know the size of the brass wire of which you are going 
to make the rods which pass down into jars. 

Having got so far you will be anxious to see how 
the parts you have made fit together, so, if you like, 
you can start assembling. The first thing to do is to 
fasten the wooden hubs to the glass plates. This can 

D 






50 Something to Make 

be done with marine glue or, better still, with bi¬ 
chromate glue. You can easily make this yourself. 
Place a small quantity of good sheet glue in a cup 
and fill the cup with water. When the glue has 
taken up all the water it will, pour off the surplus 
water and cover the moist and swollen glue with glacial 
acetic acid which you can obtain from any chemist 
who stocks photographic apparatus and chemicals. 
Now heat the mixture, and when it is reduced to 
the condition of a smooth liquid, add to it a teaspoon¬ 
ful of bichromate of potash (potassium bichromate). 
You can get this also from a photographic dealer. 
Bottle the glue and keep it in the dark, for sunlight 
will set it as hard as cement. 

With this glue fix the hubs to the glass plates 
on the same sides as you have pasted the sectors, 
taking care to get them exactly in the middle of the 
plates. Let them stand, with weights on them until 
they are set and hard in place. Meanwhile you can 
be fixing the supports and other parts to the bottom 
board. 

As I have already explained, the supports—Fig. 5— 
can be fixed to the bottom board in several different 
ways. The only essential is that they shall be abso¬ 
lutely firm. In my drawings I have indicated the 
simple expedient of slipping them into position on 
each side of the hole in the bottom board and 
securing them by means of long thin screws. Make 
the holes for the screws carefully so as not to split the 
wood. The spindle at the top will help to keep them 
braced, and that is one of the reasons why I have 
suggested keying the spindle into the supports. 

You must now procure or make your spindle 






Electrical Things to Make 51 

and the axle for the wheels. These can be either of 
wood or metal. In my machine they are made of 
pieces of ths steel 7 in. long. Half an inch from 
each end of your spindle drill a hole J in. in diameter 
to take the brush holding rods. By looking at Fig. 1 
you will see that these rods are at an angle of 90° to 
each other, so you must drill your holes to make an 
angle of 90° one with the other. In other words the 
holes must be at right angles to one another. 



O 



Fig. 13 


Now you can fix your plates in position. You 
will remember that in making the hubs I told you 
that you should leave their bushings until you lit the 
plates up. It will probably have occurred to you 
that it would be a good plan to try the bushings on 
the spindle before you fix the hubs to the plates. If 
you have done this you will have made the necessary 
adjustments. Probably you will have found that 
the bushings should project from the hubs a distance 
of in. on the flat sides. This will bring them to- 






























52 Something to Make 

gether in the centre so that they just touch. If it 
doesn’t you can adjust them to the right length. It 
is a good plan to thread a thin leather washer, well 
greased, on to the spindle so that it comes between 
the two bushings and holds them apart, but this is 
not absolutely necessary. Another good thing to do 
is to cut two washers of 2 in. diameter out of leather or 
several sheets of paper pasted together and varnished 
with shellac varnish. Make a hole sufficiently large 
in the centre of each and slip them over the hub 
bushings. This also is not absolutely necessary, but it 
helps to make a nice efficient job of the machine. If 
you put these big washers on, fix them to the insides 
of the plates—the side away from the tinfoil sectors, 
with shellac varnish. 

Having put up your plates and fixed the spindle 
so that were the two holes the hands of a clock, 
those on the front of the plates would point to 
10.30 and 4.30 o’clock, and those on the back to 1.30 
and 7.30 o’clock, you can proceed to put in the wheels, 
The spindle for these goes through the lower hole of 
the supports, and the wheels must be fixed and keyed 
on to the spindle. For the front of the spindle you 
must make a handle to enable you to turn the wheels, 
and the front end of the spindle must project suffi¬ 
ciently far to allow the handle to clear the edge of the 
bottom board. In fixing the wheels take care that 
the grooves on their edges come exactly under the 
grooves of the hubs. When you are satisfied that 
this is right, and not till then, you can cut the key- 
ways in the spindle. The spindle should be 7 in. 
long. Mine is made of in. steel rod. Wood or 
brass tube will serve equally well. 








Electrical Things to Make 


53 


Now put a band of string or round leather over 
the front wheel and front hub. Pass it straight over 
and join up the ends fairly tightly. On turning the 
handles and revolving the wheels the front plate will 
revolve in the same direction as the handle, which 
should be turned “ clockwise ” or in the same direc¬ 
tion as the hands of a clock move. For the machine 
to work, the back plate must go round in the opposite 
direction. To do this you must cross the driving 
band from the back wheel to the back hub, so that 
the portion of the band that comes from the right 
side of the wheel goes on to the left side of the hub. 
Connect up tightly as before. Now turn the handle 
and you will find that the front plate is turning 
clockwise and the back plate is turning “ counter¬ 
clockwise,” or in the opposite direction. 

So far so good. Now for a little more metal work 
and our Wimshurst machine will be finished and ready 
to make electricity for us. To complete the machine 
you will want 2 ft. of ^ in. brass rod, 3 ft. of f in. 
brass tube or rod, 3 1-in. brass balls, 3 f-in. brass 
balls, 2 J-in. brass balls, and 2 f-in. brass balls. 
These can be obtained for a few pence from Messrs. 
Scientific Appliances, or any other maker of electrical 
apparatus. You will also require sufficient 
brass rod or J-in. sheet brass to make the U* 
shaped collector holder shown in Fig. 10. I have 
shown this made of sheet brass ; but rod is really 
better, besides being easier to work. In making 
these High Tension machines you must remember 
that they are always liable to discharge, when in 
action, from any sharp corners or edges, so if you make 
this piece of sheet metal you must round the corners 







54 


Something to Make 


nicely to prevent this waste of energy. When work¬ 
ing my machine in the dark I have seen the whole 
of one edge of one of these U-shaped pieces brush 
discharging, which, of course, lessens the length of 
the spark across the proper gap. The only way to 
prevent this is to coat the edges with thick black paint. 

On my drawing of the U-shaped brush holder 
I have given all the essential measurements, so that 
you can make the pair you will require in the way 
most easy to you. The brushes are made of un¬ 
twisted pieces of brass picture wire and are secured in 
the holder with either plugs of wood or else soldered 
in. I prefer the small wooden plug method, for then 
they can be easily replaced if they go wrong. The 
length of these brushes should be just enough to 
bring them close to the glass plates without touching. 
In Fig. 4 I have shown one of the holders in position 
on top of its supporting column of glass, wood or 
ebonite, whichever vou have made it of. It is held 
in place by a £-in. brass ball to which a brass screw 
has been soldered or brazed. You should make a 
pair of these holding down balls, as shown in Fig. 11. 
They also serve as a connexion with the Leyden 
jars, so you must braze or otherwise fasten to the 
ball a length of brass tube in. diameter, and to 
the other end of the tube a J-in. brass ball through the 
centre of which, as indicated by the dotted lines, a 
hole is bored a little more than J-in. in diameter. 
This is to take the Leyden jar rod, which is shown 
in Fig. 9. This rod is made of J-in. brass, 8^ in. long* 
You want two of them. The balls on the ends are 
|-in. I have shown them fixed to the rod by screw¬ 
threading it and the ball. You can braze them on 







Electrical Things to Make 55 

if it is more convenient. Don’t forget that the 
Leyden jars are not essential to the machine. It 
will work without them, so you can put off making 
them till the very last if you like. 

The next thing to make are the two neutralizing 
brush-holders and their brushes. One of these com¬ 
plete is shown in Fig. 12. They are of T ^-in. brass 
tube. The distance between the bent ends is 8 in., 
and the ends should curve over about lj in. These 
are all the dimensions that are necessary to bear in 
mind when you are making these parts. The 
brushes are of untwisted brass picture wire and must 
be sufficiently long to make thorough contact with 
the tinfoil sectors on the plates and sweep them 
thoroughly. The brushes should be fixed in the tubes 
with wooden pegs, as I have explained in the case of 
the collecting brushes. The tubes fix in the holes 
in the plate spindle, and must make an angle of 
90° one with the other. They must be fixed quite 
firmly. This is the other reason why you should 
“ key ” the spindle in position. 

We have very nearly reached the end of our 
labours now. The only things that remain to be 
made are the two discharging rods. These require 
each 9 in. of T %-in. brass rod or tube. One is shown in 
Fig. 13. The ball through which the rod passes to 
the wooden, or ebonite, handle is 1 in. in diameter 
and to it is brazed a l£ length of f-in. tube. This 
fits over the end of the split piece of the U-shaped 
holder for the collecting brushes shown in Fig. 10. 
Reference to Fig. 1 will give you the effect when 
they are in position. 

Viewed from the back, the discharger on your 








56 


Something to Make 

right should have a 1-in. brass ball at the end, and 
that on your left a f-in ball. The only things you now 
require to finish the machine are the shoes or other 
means of keeping the Leyden jars in position. If 
you make shoes, as shown in Fig. 1, paste a piece of 
tinfoil in the bottom of each. If the jars are to stand 
direct on the bottom board paste your tinfoil to 
that. 

Now put together the parts you have not assem¬ 
bled, by reference to Figs. 1 and 4, and you are ready 
to work the machine. Remove all dust from it with 
a silk handkerchief and warm it in the sun or before 
a fire. Have the discharging balls well apart and 
turn the handle fairly fast to the right. In a few 
seconds you should hear a small hissing and crackling 
sound, and, if it is dark, you should see faint blue 
sparks where the brushes touch the plates, and on the 
ends of the collecting boxes. Now, still turning the 
handle, bring the discharging balls together until 
they are about an inch apart. Immediately sparks 
will begin to leap across with a sharp snapping sound. 
Continue to draw the balls apart until the gap is too 
big for the spark to pass. If the Leyden jars are in 
place, the sparks will be thick and bright and should 
occur at the rate of two or three a second. If the 
Leyden jars are not in action you will get a contin¬ 
uous stream of thin bluish sparks. You can throw 
the Leyden jars out of action at any time by with¬ 
drawing one or both of the rods from the jars. 

Don’t forget that when the machine is working 
it is generating high tension electricity, and that 
each spark means thousands of volts of energy. 
Unless you want a shock that will surprise you with 








Electrical Things to Make 57 

its severity, don’t touch any metal part of the machine 
without first bringing the discharging balls together, 
when the machine ceases to work, even though the 
handle is being revolved. 

Standing at the front of the machine, where the 
working handle is, one of the top sectors on the plate 
farthest from you has a slight positive charge of 
electricity. As it moves towards the left it will come 
opposite the place where one of the front sectors is 
being touched by the neutralizing brush. The result 
will be that, by influence, the sector that is being 
touched will acquire a light charge of the opposite 
kind of electricity. In other words, it will be charged 
with negative electricity, which charge it will carry 
onwards towards the right. When this negatively 
charged sector comes opposite the place where one 
of the back sectors is being touched by a brush, the 
back sector will collect a positive charge. At the 
bottom of the plates the reverse is taking place. The 
right-hand collecting brushes collect positive elec¬ 
tricity, and the left-hand collecting brushes take up 
the negative electricity. When sufficient has accu¬ 
mulated to make the difference of potential great 
enough sparks will break through the air across the 
sparking gap between the discharging balls. 

With the machine I have described you ought to 
get anything up to a 4-in. spark, and you can do 
with it anything you can do with an induction coil, 
giving a spark of a similar length. You will not 
always be able to get a spark so long, for the machine 
is subject to the influence of the atmosphere. On 
damp days it will not work so well unless it is kept 
thoroughly warm and dry. 








58 Something to Make 

With this machine you can work small X-ray 
tubes in the way described in the article on “ How 
to Make an X-ray Apparatus.” You can illuminate 
small vacuum tubes and do all the many won¬ 
derful and interesting experiments that are described 
in books on electricity and physics under the heading 
of Static Electricity. 

You will find that you get more fun out of your 
machine if you work it in the dark or the half dark. 
When it is going well it seems to fairly glow with 
points and flashes of light. 

A thing that always interests my small friends, 
and bigger ones too, is what I call my “ imitation 
thunderstorm.” I cover the ends of the discharging 
balls with screwed up balls of newspaper or clouds 
of cotton wool lightly tied over the balls with silk 
or twine. Then I begin to work the machine and 
slowly bring the two clouds near to one another. 
When they are about three inches away from one 
another they begin to glow at the ends of any little 
points of paper or wool that are projecting. Then 
the storm begins. Between the two clouds a stream 
of most realistic miniature lightning breaks out» 
branching and forking just like the real thing. The 
performance is always greeted with applause by the 
spectators. 

There are many other simple and ingenious 
experiments you can perform, but I must leave 
you to find them out for yourself from books. 






MAKING A NEEDLE TELEGRAPH 

APPARATUS 


O F course there is nothing new in the idea of 
possessing a home-made telegraph system. 
Old boys of sixty or so may remember having had a 
shot at making one in their 1st Form days ; but 
their recollections of the success of the enterprise are 
prone to be a trifle hazy. That is because so much of 
the exasperation attendant on failures and semi- 
failures of the past is quite soon snowed under by 
the kind oblivion of the years. 

But dud results in this direction must have been 
the rule rather than the exception, simply because 
the instructions given in boys’ books of earlier days 
were too often framed in the attempt to imitate the 
real thing too lavishly. 

It is true that the G.P.O. single-needle instrument 
is simplicity itself ; but it is, nevertheless, a delicately 
accurate piece of skilled labour, electrical and me¬ 
chanical : a roughly made copy of it simply won’t 
work. 

If you glance at an illustration of this thing in the 
“ Telegraphy ” article of a big encyclopaedia you will see 
a straightforward-looking job enough—just two neat 
oblong coils of covered wire with a magnetized needle 
suspended between them on a pivoted axle which 
carries a pointer needle, and there you are ! Quite so. 
But even the winding and secure fixing of those two 
open coils is not so easy as it looks ; and as to the 
needle pivoting ? Ah, that is an over-exquisite 

59 


6o Something to Make 

business for prentice hands (having thumbs in excess). 
Do not doubt it. 

Our objective, I suggest, is the possession of a pair 
of self-contained, robust little telegraph instruments 
which will act briskly and reliably under adverse 
conditions, if need be. (Even such, for example, as 
would subsist if one or both of our “ stations ” were 
temporarily installed in a swaying tree-top.) No 
gently-dipping, sluggish needle would serve in such 
case, the essentials being that our sturdy, active little 
pointers shall swing vigorously to right or left, obedient 
to the touch on the pedal keys, emitting a crisply 
audible tink-tenk against the two limiting stops, or 
tin “ sounders,” on the dial. 

To secure these desiderata, established methods of 
expert construction must be abandoned in favour of a 
cruder design : a homelier device possible of creation 
by two sets of those pan-thumb digits aforesaid. 

Figs. 1, 2 and 3 present the front, side and back 
elevations of a self-contained instrument specially 
designed for this work. It is self-contained in the 
full sense of being complete in itself, combining the 
means for sending and for receiving signals in the 
Morse code, together with the electrical means for 
their transmission also. Thus, efficient telegraphic 
communication between two reasonably distant points 
can be established at short notice simply by connecting 
two such sets by lengths of line wire (or by single wire 
and “ earth-return ”), no separate batteries or other 
apparatus being required. 

Now for a general explanation. On the front of 
the instrument (Fig. 1) is seen the pointer p, pivoted 
vertically in the centre of the dial, between the two 





Electrical Things to Make 61 


stops or tin¬ 
plate sounders 
s s. Below the 
dial are the two 
pedal keys k 
(which, despite 
their inappro¬ 
priate name, 
are operated 
by the fingers 
and not by the 
feet!) At the 
bottom—as in 
a pigeon-hole 
of a desk—is 
stowed our 
familiar friend 
the three-cell 
flash battery 
recruited for 
special service. 
(The front 
panel w h i c h 
secures the 
battery is omit¬ 
ted from the 
drawing; it will 
be referred to 
later.) Fig. 2 
is a side part 
section in which 
farther (see k), 
(see f-l c) with 



* i " '• \% III 
•:> .. 


co 

'ci 

£ 



hi msm 

the keyboard detail is taken a step 
and the battery is seen edgewise 
one of its two connexion strips 
























































































































62 Something to Make 

pressing against a screw point. So much for the 
desk-like horizontal part. In the vertical portion 
of the body some of the simple mechanism of the 
pointer r is disclosed (edgewise), and this should 
be examined along with the back view, Fig. 3, 
which shows the same in plan. The pointer p is 
a strip of thin sheet brass, say | in. wide and 2| in. 
long. This is sloped to a fine point at one end (see 
Fig. 1) and bent twice sharply at right angles (Fig. 2). 
A tailpiece (t, Figs. 2 and 3) of the same sheet brass 
is soldered to the face of the inner right angle bend of 
p, and then p and t are drilled through to receive the 
pivot pin p, which is forced into the back rail h, r and 
t thus swing freely on p , a little end play being 
allowed between the pin head and a spacing tube r 
(which may be a long glass bead called a “ bugle,” or 
several ordinary rounded beads will serve). 

On the back face of the tail-strip t is fixed a 
magnetized steel needle m n, with one end projecting 
slightly beyond the lower extremity of t. e m is an 
electro-magnet; this you may acquire ready-made 
from an old electric bell, but if you “ play the game ” 
you will make it yourself from the instructions to be 
given. 

Observe closely that in Figs. 2 and 3 the lower 
extremity of the needle m n hangs centrally between 
the sloped pole-ends of the electro-magnet e m, and 
that when the pointer combination p t sways to right 
or left on its pivot-pin p, the arc described by the 
lower end of m n will swing it very closely past the 
poles of e m, but without touching them. 

This near swing of the needle-end, without touch¬ 
ing, is a factor of importance, as promoting the prompt 










Electrical Things to Make 63 


action of the pointer to the key-signals and its firm, 
ringing impact against the sounder stops s , Fig. 1, 
when m n meets the attractions and repulsions of 
E M. 

At this point the rationale of the whole device 
must be briefly touched upon. Of course you know 
already that the like poles (say n) of two magnets repel 
each other, and that the unlike poles (n and s of the 
same) attract each other. You know, too, that the 
so-called permanent magnet is made of hardened steel, 
and that the electro-magnet is of soft iron which only 
becomes temporarily magnetic when electric current 
is sent flowing through coils of insulated copper wire 
wound upon its limbs. The poles (n s) of steel 
magnets are permanently fixed at their extremities, 
but the poles of electro-magnets can be changed over, 
instantly, by reversing the direction of the electric 
current in their coils. 

Now supposing that the needle m n, Figs. 2 and 
3, were a piece of soft iron wire, it is obvious that it 
would be attracted by either of the pole ends of e m, 
indifferently (whichever happened to be the closer 
to it). But m n is of hardened steel, permanently 
magnetized, and so has two dissimilar poles of its 
own, say n downwards and s upwards. While all is 
at rest the lower pole-end will hang vertically (by 
gravity) midway between the two inert soft iron 
limbs of e m, but directly electric current is passed 
through the coils of the latter it becomes a strong 
magnet, its opposite sloping pole-ends exerting a 
powerful, attractive, and repulsive double influence 
on the depending single pole of the needle-magnet 
suspended between them, which, consequently, will 








64 Something to Make 

be swung vigorously to the right or left according to 
the direction of the current through the coils. 

Current is set flowing instantaneously in either 
direction by depressing one or other of the keys k ; 
which, together, constitute both a contact maker and 
a commutator. That is to say, when two similar 
instruments are connected by line wires, the operator 
at one station touching the right-hand key sends 
current from his battery in a given direction through¬ 
out the system, swinging the pointers at both stations 
to the right and clinking the characteristic muted 
note of the tin sounder on that side ( tink ). Touching 
the left key reverses the current and the needle-swing, 
and the distinctive sounder note ( tenk ) is struck. 
After a little practice messages thus received in 
Morse code can be read off either by sight or 
hearing. 

The casings may first be made, and as two 
identical instruments are required they are best built 
concurrently. The drawings suggest the use of wood 
i in. thick throughout, but 3-ply fretwood of thinner 
substance will serve; cigar-box wood, being soft, is 
less suitable. The baseboard a is 5 in. long bv 3 in. 
wide, the front of the vertical body b , which carries 
the dial, is 4| in. high by 3 in. wide, the cover of the 
battery box c, and that of the keyboard d, are 3 in. by 
3 in., the strips forming the sides of the battery box 
are 1 in. wide by 3 in. long ; the strips g, for the sides 
of the vertical body, are f in. wide by 4J in. long, the 
top of the body f is 1 in. wide by 3 in. long, and the 
backboard e is 4J in. high by 3 in. wide. The key¬ 
board cover d is raised above the battery box cover 
c, by three strips of J in. wood, \ in. wide. 






Electrical Things to Make 65 

Time will be saved by planing, marking, cutting out 
and squaring up in duplicate all the wood required for 
both casings ; this will also ensure a close similarity 
of appearance for the pair. The crudely drawn 
graining lines of Fig. 1 show direction the wood 
(other than 3-ply) should be cut, and for those little 
skilled in cabinet work butt-ended glued and nailed 
joints throughout are recommended as simple, strong 
and sightly, if reasonable care is bestowed on the 
preparation of the work. (Preparation of the de¬ 
tached parts means everything in their assemblage; 
work by the foot-rule, the marking-gauge and the 
set-square, planing all edges flat and all corner angles 
truly rectangular. Then the putting together will 
almost take care of itself.) Use freshly melted 
Scotch glue for the joints : it should be very hot 
and mixed rather thin. The nails or brads may 
be J in. or f in. long and as thin as procurable ; all 
nail-holes should be made with a fine bradawl and the 
joints fitted before the glue is applied (quickly) and 
the nails driven home a shade below the surface with a 
suitable punch. Begin by fixing the vertical strips g to 
the back of the body b, then put on the top piece /. 
Next attach the finished vertical body to the base¬ 
board a , the face of b being set on a line squared across 
a at exactly 3 in. from one end (see Fig. 2). Then 
fix the two side strips of the battery box and after¬ 
wards its cover c. Proceed thus far with both the 
casings and put them aside to dry and harden 
thoroughly. 

Fig. 4 is a plan of the keyboard, the detail of 
which is partially shown in figures 1 and 2. In this 
plan (Fig. 4) one looks down upon the top of the 

E 





66 Something to Make 

instrument with the keyboard cover d, and also the 
vertical body cover f f removed. 

The pivoted pointer, tinplate sounders, etc., are 
omitted in order to show the electro-magnet e m, fixed 
in position by a wooden strip laid across the bobbin- 
windings and secured by a wood screw passing 
between them. The two wood blocks on which the 
pivot bar h is supported are also seen glued into the 
angles of the vertical casing—these are grained for easy 
identification ; the two screws by which h is attached 
are seen in Fig. 3. The keyboard strips i are glued 
and nailed to the battery box cover ( see also Figs. 1 
and 2), but before this is done they must be slotted as 
shown to receive the two key springs k , and the cross¬ 
bar contact strip k 1 . 

The edgewise view of the key projected to the right 
of Fig. 4 shows that the k springs are recessed into the 
wood deeper than are the ends of the contact bar A; 1 
in order that the former may pass under the latter, 
and that the keyboard cover d (Fig. 2) may bed down 
flush upon the wood strips i ; d may be attached by 
three small screws for easy removal if necessary. 

Two slots to accommodate the key buttons must 
be cut in the cover. The key springs k and the con¬ 
tact strips k l and A; 11 are of hammered and polished 
sheet brass \ in. wide. Their ends are drilled and 
countersunk for small wood screws, and although 
their wire connexions may, if desired, be simply 
screwed down under them, it is better practice to 
solder a length of covered wire to each of them as 
suggested at w 9 top corner Fig. 4. 

In fitting the springs k must be given a strong 
upward bias, sufficient to keep them firmly pressing 






Electrical Things to Make 67 



Fig. 4 



against the upper contact bar k 1 ; when pressed 
down they must detach themselves from k 1 before 
making contact with the under contact A; 11 . The 
semicircular wooden buttons are secured to the ends of 
the key springs by a couple of fine screws, or nails (see 
projection, Fig. 4). The pointer, its tailpiece, pivot 
holes and magnetic needle M N are drawn of double 
dimensions at Fig. 5, which elaborates the description 
of this part already given. The needle m n, once 
hardened and magnetized, must not be soldered to the 
tailpiece because heat destroys magnetism. It may, 
therefore, be attached with sealing-wax, varnish, 
shellac varnish or even seccotine ; additional security 
will be ensured by two lashings of silk thread s l , 
passed through fine holes drilled in the brass, before 
applying the adhesive. 

For the pivot itself (p, Fig. 2) a large brass pin, 





























































































68 Something to Make 

known in the household as a “ blanket pin,” will 
serve ; this is pressed firmly into the hardwood back- 
rail h, as previously explained, a fine hole being 
drilled to receive it; the entering portion of the pin 
may be slightly roughened with a file and dipped in 
varnish or seccotine before fixing. Alternatively, a 
stout brass back-rail may be used, the pin being 
soldered into it after mounting the pointer and its 
spacing washers (glass beads) upon it. A centre-bit 
hole through the centre of the dial § in. to in. in 
diameter will be large enough for the entry of the 
pointer from the back. 

The magnetic needle M N is lj in. to lj in. length, 
file-nieked and broken out from the central portion of 
a very stout darning needle (the eye and point being 
discarded). Alternatively, a compound magnet may 
be formed of from three to six finer sewing needles, 
separately magnetized and then bundled together. 
After nicking and snapping off the points and eyes all 
may be reduced to an equal length by rubbing down 
the ends on a grit stone (such as a stone doorstep or 
sink). 

In modern practice permanent magnets are made 
from special steels (alloyed with tungsten, vanadium, 
etc.) and quenched to extreme hardness ; but for our 
purpose the quality and normal temper of the steel 
used for the best sewing needle serves fairly well, 
absorbing a sufficient density of magnetism and re¬ 
taining it for considerable periods. 

To magnetize, grip the needle about midway, lay 
it on one pole of a large magnet (or electro-magnet) 
close up to the finger and thumb ; then draw it off 
the pole. Replace and withdraw repeatedly, say a 







Electrical Things to Make 69 

score of times, then reverse the grip and treat the 
opposite end of the needle similarly on the opposite 
pole of the large magnet. When attaching the two 
needles (or compound needles) to the two tailpieces 
be sure to locate similarly their respective like poles 
(say N downwards and s upwards). 

If in doubt as to this, test the poles by their mutual 
attraction or repulsion, remembering that unlike poles 
attract and like poles repel. Alternatively balance 
one needle at a time on a disc of cork floated on clean 
water in an earthenware basin ; the rafted needle will 
swing and come to rest pointing magnetic n and s, the 
end which points n being the s pole of the magnet. If 
while one needle is floating one end of the other is 
approached, the floating needle will swing round to 
present its unlike pole to the other. 

The electro-magnet E m is bent V shape from a 
4 in. length of ^ in. diameter common iron (once 
known as “ nail rod ” by ironmongers). On no 
account must any variety of fine iron (such as so- 
called “ mild steel ”) be substituted for common iron. 
E m measures If in. from the bend to the sloping pole- 
tips, which stand about \ in. apart. The iron may be 
heated before bending over a piece of b in. diameter 
iron bar. Straighten both the limbs and make them 
parallel, cut off and slope the pole ends with a file, 
smooth off all over, and then anneal the two finished 
magnets by placing in a seamless tin box (a tooth 
powder or blacking box) secured with iron wire. 
Put this box in the heart of a good fire overnight to 
become and remain red hot for an hour or two and 
then very slowly to grow cold as the fire dies out. 
Next morning the box-protected magnets will be in the 





70 Something to Make 

softest annealed condition to which iron can be 
brought, ready to accept and to reject temporary 
magnetism instantaneously. 

Straighten a few inches of the same in. nail rod, 
file its ends square and make smooth all over. Use 
this as a former to roll the paper core tubes of the 
bobbins (see Fig. 8). Cut four strips of writing paper 
21 in. long by 1J in. wide, roll each on the former 
bar, mark the line of the first overlap, coat the rest of 
the strip with hot thin glue or strong gum ; warm the 
former bar, rub it with french chalk and roll the 
paper slip tightly and evenly upon it, consolidate by 
rolling on the bench under a piece of smooth board ; 
slip each tube off the former and put aside to harden 
thoroughly. From thin wood cut two cheeks for each 
bobbin ; these may be either discs or squares § in. in 
diameter with central holes of a size to receive the ends 
of the paper core tubes tightly. Glue the discs on to 
the tube ends to measure 1 in. apart over all, allow 
to set and harden, then mount again on the iron 
former and trim off the surplus projecting ends of 
the tubes with a sharp knife. Place the completed 
bobbins in a cool oven for an hour to drive off all 
moisture, then immerse for a few minutes in melted 
paraffin-wax (paraffin candle ends will serve), drain 
off, cool and polish with a dry cloth. Bobbins cannot 
be properly wound with fine insulated wire by hand— 
make a little windlass like that seen at Fig. 7 with 
a push-through axle just fitting the bobbin (shown 
dotted). The iron tube former may be used for this. 
Procure four ounces of No. 28 gauge double silk-covered 
copper wire from an electrician’s stores (cotton cover¬ 
ing is cheaper, but it is too bulky for small work). 









Electrical Things to Make 71 

Alternatively, enamelled wire can be used, but it 
requires extra care in winding. 

Mount the store spool (on which the wire is 
purchased) on a bent wire “ horse ” driven into two 
holes in the bench in a convenient position. Drill a 
small hole through one of the bobbin’s cheeks close to 
the tube, pass three inches of the insulated wire 
through this, coil it up neatly, mount the bobbin on 
the axle between the windlass uprights, revolve the 
crank (over and away from you) with the right hand, 
and guide on the wire with the left hand. Wind 
quite evenly as a reel of cotton is wound, layer after 
layer until the bobbin is nearly filled level with the 
flanges (see Figs. 2 and 3). Count the layers, winding 
all the bobbins alike, and all in the same direction. Tie 
down the finishing ends of each winding with silk 
thread, and finally soak all the wound bobbins in melted 
paraffin wax after warming them through in a very 
moderately heated oven for one hour. Remove from 
the wax, drain, slightly warm the iron magnets and 
push the bobbins on to their limbs; snip off the inner 
or beginning ends of the windings to about 1 in. in 
length, strip off | in. of their silk or enamel insulation, 
polish them, twist their ends together and solder with 
a touch of a hot, clean soldering bit. (Use only resin 
and not any other soldering flux for jointing wires.) 
A reference to Fig. 3 will elucidate these instructions, 
w representing the inner winding ends soldered 
together, and w 1 the outer ends ready for connexion 
elsewhere. 

The tin sounders, s , Fig. 1, are cut out from light 
gauge tinplate (a condensed-milk tin provides material) 
according to the enlarged dimensioned plan a , Fig. 9 ; 








I 

I 


72 Something to Make 



fHHHk 

"Mf 


Z 1 rt ** 


7~e t u 7~n 


Fig. 6 



b and c of the same are end views of the two sounders 
bent to shape ; either the semi-cylindrical or rectangu¬ 
lar bend may be adopted at option. The finished 
sounders, when attached to the dial (s, Fig. 1), will 
probably emit a dissimilar note if lightly tapped, but 
if the tone is insufficiently distinctive, that of the left 
hand one may be lowered by snipping or filing out a 
notch in the down-bent edges. Alternatively, a bead 
of solder applied to the inside of the right hand 
sounder will raise its tone. 

Fig. 6 explains both internal and the external 
wiring of the two instruments. The external or line 
connexion running between the stations is suggested 
by broken lines, lettered line and return , and the in¬ 
ternal or baseboard connexions are drawn in solid 
line. The two sets are identical in all respects except 
that the terminals of each are lettered in opposition 
to each other, that on the left of the drawing 
reading L R (line and return) and the other R 1 L 1 . 
When coupling the sets, all the 44 linesman ” needs 
to remember is to connect the L and L 1 terminals 











































Electrical Things to Make 73 

by one wire and the R and R 1 terminals by the 
other. 

The practical application of this diagram (Fig. 6) 
will be observed when the parts are fitted into the 
casings; then bradawl holes can be pierced through the 
woodwork in unobtrusive places through which the 
several wires are passed from point to point. The 
keyboard crossbars k 1 and k 11 are wired direct to the 
two screws which engage the contact strips of the flash 
battery (see Figs. 2, 3, 4 and 6). The holes for these 
two wires are punctured into the top angles of the 
battery box right and left, two more holes being 
made through the vertical board b (Fig. 2). The 
wires, being neatly stowed in the angles of the battery 
box, emerge behind b, where their ends are secured 
between heads and washers of two battery screws 
(Figs. 2 and 3). 

The left key k is wired direct to the left-hand 
terminal, requiring one hole through b and another 
through the baseboard a below it, the wire passing 
to the terminal in a groove cut in the bottom of the 
baseboard. The right key k connects to the left 
bobbin of the electro-magnet E M (Fig. 6), for which 
one hole through b (Fig. 2) only is required. 

The right bobbin is wired direct to the right-hand 
terminal, necessitating one hole through the base- 


1 

/f&oZ2>Z7,) 

I 

P<zpe-r 'tuhe 

^-IVood discs- 




Fig. 7 


Fig. 8 



































Something to Make 


' 74 

board a and a groove leading to the terminal. The 
two grooves incised in the baseboard can be filled in 
with resin or sealing-wax, applied with a hot iron 
after the wires are in place. Standard 3-cell flashlamp 
batteries have one long and one short contact strip; 
the longer strip must be snipped off to a length equal 
to the short strip, so that they may both be bent 
towards each other without touching. Then each will 
bear against the blunted end of one of the two con¬ 
tact screws at the back of the battery box, wired to 

the key crossbars k l and 
k 11 (Fig. 4). 

Referring to Fig. 6, it 
will be seen that the positive 
pole + of the battery b 
connects with the bottom 
crossbar k 11 and the nega¬ 
tive pole — goes to the top 
crossbar A; 1 . It is of im¬ 
portance, therefore, that the 
batteries shall be inserted in 
the box right way about. The negative or zinc pole 
(—) of a flashlamp battery is almost invariably that 
which has the longer contact strip, which emerges 
from the pitch seal close to the edge of the wrapper. 
When inserting battery the — strip must be to the 
right. A wooden panel which keeps the battery in 
place is not shown ; it consists of two pieces of J in. 
wood glued together; one portion measuring 1 in. wide 
by 21 in. long pushes into the box, and the outer 
strip, 3 in. long by lj in. wide, abuts on the box 
edges and is attached by two thin screws | in. long. 
Assuming, now, that all the instructions have been 



Fig. 9 

























Electrical Things to Make 75 

followed accurately; that the magnetic needles 
M n have been attached n pole downwards ; that 
the four bobbins have been wound similarly, the 
beginning ends of the windings having been passed 
out through holes in the left bobbin cheeks (as at w. 
Figs. 7 and 8) and the windlass revolved over and 
away from the operator, then the complete connexions 
shown at Fig. 6 will produce correct working results at 
the first trial. As shown, a touch on the right-hand 
key at either station will produce a right-hand 
deflexion of both the pointers, the left keys effecting 
a left deflexion. 

Connected by No. 20 gauge insulated copper lines, 
vigorous signals should be obtainable between 
stations, say, 200 yards apart, or over a single line 
and 44 earth ” return effected through a main water- 
pipe or gas-pipe. (A clean metal-to-metal connexion 
with the nearest pipe at each station should be made 
with a length of wire to the R terminal.) 

For short distances No. 22 gauge twin-conductor 
electric bell wire is convenient; twin flexible is even 
more so. Stout galvanized iron bare wire is cheap and 
fairly satisfactory for an outdoor line. It must be 
suspended on insulators (improvised from glass bottle 
necks mounted on stakes, the latter being nailed 
to fences or lashed to trees). The line itself is lashed 
to the side of an insulator with a finer gauge of 
similar wire. The correct connexions at the ends of a 
long line can be determined in the first place by both 
operators persistently tapping their right-hand keys at 
intervals until, by changing over, right-hand deflexions 
are obtained at both stations. 

The Morse needle alphabet is given by way of 








y6 Something to Make 

conclusion. It is more quickly learned than might 
be supposed, but messages can be sent and received 
(slowly) long before it is properly learned. The sender 
spells out the signs from the alphabet, and the 
recipient “ shorthands ” the deflexions on paper as 
they appear, “ translating ” them afterwards. The 
right-hand deflexion is usually represented by a long 
stroke (—) and the left by a shorter stroke (-). Take 
for example the word— 

C II U M S 


and observe how easily the Morse signs below could 
be pencilled down while the pointer “ tink-tenked ” 
them out. 


THE MORSE NEEDLE 

ALPHABET 

A — 

J - 

s ... 

B —• • • 

K - 

T — 

C- 

L *—* * 

U- 

D- 

M - 

V_ 

E . 

N — 

W - 

F • •—• 

0- 

X- 

G- 

P- 

Y- 

H .... 

Q- 

Z- 


I • • R .— 






HOW TO MAKE AN X-RAY APPARATUS 


A COMPLETE apparatus for taking X-ray photo¬ 
graphs can be made at home at comparatively 
small cost. The only thing that cannot be home-made 
is the X-ray tube itself; but as second-hand tubes 
in quite good enough condition for small work can 
usually be purchased for a few shillings there is no 
reason at all why my readers should not enjoy the 
fascinating hobby of “ Skiagraphy.” 

The apparatus consists of an X-ray tube and stand, 
a battery of electric cells and an induction coil, or 
“ sparking coil,” as it is sometimes called. 

Most important is the induction coil, and once 
you have made it you will have a piece of apparatus 
that will be useful to you for many other interesting 
experiments besides taking skiagrams, so it is worth 
while taking pains and making it well. For the 
benefit of my readers I have designed an induction 
coil that is both strong and simple. Properly made 
according to directions, it should give a spark of 
at least an inch and a half. 

Before you start to build it you should acquaint 
yourself with the principle on which the coil works. 
It is quite easy to understand, as I will explain. 

An ordinary electric battery gives a current of 
very low pressure or “ voltage,” as it is called. For 
working an X-ray tube you must have a high-pressure 
current. You know that if you rub together the ends 
of the wires from a bell battery in the dark you will 
see a tiny blue spark. If you pass this current 

77 


7 8 Something to Make 

through an induction coil you increase the pressure, 
so that the spark will be very strong, and will leap 
across an inch or more of air. This is because the 
pressure of the current has been intensified. 

Figure 1 will show you, in the form of a diagram, 
how this is done, b represents an ordinary battery of 
six or more cells. I have only shown four, but that 
doesn’t matter. A wire marked r, which is shown 
as a thick line, passes from the battery, and is coiled 
round a core which is made of a bundle of soft-iron 
wires. The core is marked a. The other end of the 
wire is connected back to the battery through the 
vibrator or contact-breaker marked v. For the 
moment don’t pay any attention to the gridiron¬ 
shaped thing marked c. I will explain that later on. 
Now trace the path of the current again. It goes 
from the battery, round the coil through the place 
marked g, where the contact-breaker spring touches 
a point, and back to the battery. 

Now directly the current flows through the thick 
wire, which is called the primary coil, it turns the 
bundle of wires into a magnet, v is made of iron, 
and is attracted towards the core A. The spring leaves 
the point g, so that there is a gap and no current can 
pass. When this happens the core leaves off being 
a magnet, because there is no current passing, v flies 
back until the point touches at g again, and the 
current flows once more, and the core is a magnet 
again. So it goes on, the contact-breaker vibrating 
very rapidly, cutting off and turning on the current. 
Electric bells work on this principle, as you know. 

Now we come to the gridiron-shaped thing 
marked c. This is the condenser. It is made of 






Electrical Things to Make 79 


sheets of tinfoil with oiled paper between. It acts as a 
kind of reservoir, and when the current is cut off at 
G it flows into the condenser and charges it. The 
current discharges back through the primary coil in 
the reverse way from that in which it flows from the 
battery. This causes the current to grow or pile 
up in the pri¬ 
mary coil. 

You will see 
that the cur¬ 
rent through 
the primary 
coil is free 
to flow from 
the battery 
and back 
again. Round 
it is wound 
the secondary 
coil, marked s 
in the diagram 
and drawn 

with thin lines. The secondary coil is not connected 



ifinnr 


Fig. 1 


in any way with the battery, and yet when the coil 
is working a shower of sparks leap across the space 
marked E, where the zigzag line is shown. How does 
this happen ? The piling up of current in the primary 
coil 44 induces ” a current in the secondary coil. It 
is something like a short distance 44 wireless,” you 
understand. Though there is absolutely no con¬ 
nexion between the two coils—if there is the coil will 
not work—a very high-pressure current grows rapidly 
in the secondary coil, and discharges across the gap e 


































































80 Something to Make 

in a shower of sparks. And it is this high-pressure 
current that you use in the X-ray tube and for other 
experiments which will be described in due course. 

In my opinion it is always best to do the hard 
and tricky parts of any job first, so that most of our 
difficulties can be disposed of early in the under¬ 
taking. We will, therefore, wind the coils first of all. 

You will want a bundle of soft-iron wire 9| inches 
long and an inch in diameter to make the core. The 
easiest way is to buy the proper wire already cut to 
length from an electrical supply shop. It will only 
cost a few pence, and will save you a lot of trouble. 

The core has to have a case or tube to cover it 
and insulate it. If you have, or can get, a tube of 
ebonite or thin glass of the right dimensions—that is, 
1 inch interior diameter and 9J inches long—so much 
the better. If not, you will have to build one of 
waxed paper. If you intend to use a makeshift tube 
of either of the two substances mentioned above, it 
will not matter if the inside diameter is a little smaller 
or a little bigger than the size given. If you have to 
build your tube, you can do it by wrapping a sheet 
of stout pasted paper round a rod of the right size. 
Wrap on sufficient paper to make your tube one-six¬ 
teenth of an inch thick in its walls. Use sufficient 
paste to make the paper stick, but be careful not to let 
any ooze on the inside of the tube, or it may stick to 
the rod and cause you trouble and loss of time. 

You should buy a quarter of a pound of paraffin 
wax. Candle ends will do almost as well, and will be 
cheaper. Melt your wax and soak your tube in it, 
being careful not to distort it in doing so. When the 
wax has set hard, you can fill your tube with the soft- 





Electrical Things to Make 81 

iron wire, and your core is ready. Fill the tube 
tightly, and file the ends of the wire quite level and 
flat. This is important. 

You are now ready to begin winding. Mark your 
tube covering the core with two circles going com¬ 
pletely round it. One should be half an inch from 
one end and the other three-quarters of an inch from 



Fig. 2 the core protrudes from the coil. For 


the primary coil you will want half 
a pound of No. 18 s.w.G. cotton-covered wire. 
(“ s.w.G.” means British Standard Wire Gauge.) 
Start your winding very carefully from the mark 
that is half an inch from the end. Before you 
begin look at Fig. 2, which shows a cute method of 
securing the wire. As you start winding on the first 
coil make it fasten to the core tube with a short tape. 
When you are binding on the second layer—which, 
of course, will come backwards over the first—turn the 
tape over the free end of the wire you left hanging 
when you started, and bind it down with the wire. At 
the same time you should insert another piece of tape 
to secure the second free end when you finish off. 





























































































82 


Something to Make 


The free ends should measure about 18 inches. 
Two layers of No. 18 wire complete the primary 
coil. 

Now you want your paraffin wax or candle ends 
again. Get the wax heated and nicely fluid. Whilst 
it is heating up, cut some strips of paper 8j inches 
wide, which is the length of your primary coil. Soak 
this paper thoroughly with wax, and wind it tightly 
round the coil until you have about twelve layers. 
Before you wind the paper on, you should pour 
melted wax over the coils of the primary until it is 
thoroughly impregnated with it. 

Now you come to the most tricky part of the whole 
operation. There is no use disguising it, the winding 
of the secondary coil is not easy, and it is best to come 
to it with the idea that it is difficult, for it is the most 
important part of the whole coil. 

For the secondary coil you need 2 lb. of No. 36 
s.w.G. silk-covered wire. Now, two pounds of this 
very thin wire is a great deal in point of length. It is, 
in fact, about three miles and a half ! Every yard of 
that wire you will have to wind carefully on to the 
coil. 

Now is the time when you will appreciate the help 
of a friend, and if the friend chances to possess a 

lathe, or you can 
* . « get the use of 

one, you will find 
your work better 
and more quickly 
done than if you 
tried to wind the 
secondary with- 


m 


Fig. 4 






































Electrical Things to Make 83 

out any help at 
all. In fact, if 
you cannot have 
the use of a 
lathe, you had 
better spend a 
little time in 
making a wind- 
i n g apparatus 
such as I have drawn in Fig. 3. It will save you 
a lot of time. 

It will save a lot of trouble, too, if you now make 
the two square bobbins that guard the ends of the 
coil. These are shown in elevation in Fig. 4 and also 
in plan in Fig. 5. They are blocks of half-inch wood 
4 inches by 4J inches. It does not very much matter 
what wood they are made of, provided it is well 
seasoned. A good wood that can be well polished 
looks nice. If you can manage it, the very best 
thing to make these bobbins of is ebonite, but that is 
a refinement and not a necessity. 

Mark off a quarter of an inch from the long side 
of each so that you have a four-inch square made up 
of three sides of the bobbin and a pencil line. Draw 
diagonals to find the exact centre of each four-inch 
square, and then mark out a circle on each bobbin the 
exact diameter of the core tube on its outside. These 
holes may then be cut, but they must be cut care¬ 
fully, for it is necessary that the core tube, with the 
core in it, should fit snugly in the holes. 

Fit the bobbins and “ chuck ” your coil, bobbins 
and all in a lathe or on the winder. Have your spool 
of wire on another winder, or so placed that the wire 



Fig. 5 


























84 Something to Make 

can come off without strain, and wind it on carefully 
in the same direction as you wound the primary. 

Leave a foot of free end when you start. It is 

* 

well to cut a narrow groove in the bobbin face—the 
inside face—and lead the free end up this, fastening 
it down into the groove with wax or shellac varnish. 
Make grooves for the primary coil ends also and fasten 
them in. The secondary free end goes up to where 
the terminal will be. The primary free ends lead 
downwards. 

The thin wire must be put on with great care, so 
that each turn is touching the one before it and none 
is overlapping. 

Between each layer you should put a sheet of 
paraffin-waxed paper, and you should pour melted 
wax over each layer of wire as well, to be certain of 
making a thoroughly good job of it. Run the wire on, 
slowly and carefully, layer after layer, until you have it 
all on, the whole two pounds of it. When that is done, 
you can heave a sigh of relief, for the back of your 
job is broken. Give the whole coil a thorough satu¬ 
rating with melted wax, cover it with several layers 
of stout waxed paper, and put it away to dry and set 
hard. The secondary coil should make a cylinder 
very nearly four inches in diameter if you have wound 
it correctly. Should you by any chance have wound 
it so that it makes more than a four-inch cylinder, 
don’t despair. Make new bobbins, or “ cheek 
pieces,” of the right size and complete your winding. 
The exact size does not matter. The great thing is to 
get the wire smoothly wound in place. 

You will now want a nice easy job, so you can set 
to work on the wooden base. For this you will want 






Electrical Things to Make 85 


a block of some good hard well-seasoned wood that will 
take a polish. It should be 1^ in. by 12 in. by 6j in. 
when finished to shape. Cut the slots to take the 
bobbins or cheek pieces at \ in. and 2j in. from each 
end, as shown in the plan and elevation. These slots 
must be J in. wide and J in. deep. It is best to make 
them a little too small in the first place than too big, 
for the cheeks must fit them very snugly. They will 
ultimately be glued in place. 

Now turn the base over and hollow out a space 
8 in. by 6 in. and § in. 


deep. This is to take 
the condenser, of which 
more anon. Finish off 
the base with sand¬ 
paper ready for stain¬ 
ing or polishing, and 
then turn to the next 
job. 

If it is possible, 
you should get hold of a u trembler ” or contact- 
breaker already made, with the platinum points 
already in position. This will save you a deal of 
trouble, and will probably make for efficiency in 
the coil. 

The plan, Fig. 5, and the elevation, Fig. 4, will 
show you the details of the contact-breaker. The 
armature marked v on the drawings should be of 
soft iron. It must be of the same diameter as the core, 
and it should be at least as thick as half the diameter. 
This means that, as we have a one-inch core, our 
armature will be an inch in diameter and at least half 
an inch thick. If you procure a ready-made contact- 




Fig. 6 


Fig. 7 




















86 Something to Make 

breaker from an electrical shop or second-hand shop 
you will probably have to fix a new armature of the 
right dimensions. I have not indicated in the draw¬ 
ings any mode of fixing the armature to the spring. 
The best way is to drill the spring and the soft-iron 
disc, and secure the two firmly with three small screws. 
If you like you can solder them together, but be 
careful not to spoil the temper of the steel spring by 
making it too hot. 

If you are making your own contact-breaker, you 
will want a piece of very best steel spring—a straight 
bit of clock spring will do—3J in. long and about 1 in. 
wide. It should not be wider than 1 in., but may be 
§ in. without harm. Reference to the drawings will 
show you that the end of the spring is fastened to the 
metal pillar “ M ” by screws. Two screws are shown ; 
but you must use three or four to make a good job of 
it. The pillar may be made of brass or steel—brass 
is the better if you can manage it. It should be \ in. 
square and 3| in. long, the bottom J in. being screwed 
to fix into the woodwork of the base. Should screw 
threading the end present difficulties, you can get 
on without it; but in that case you must make the 
hole in the woodwork a very tight fit, and secure the 
post with strong glue. 

The post that holds the adjusting screw is marked 
n on the drawings. It is the same length as the 
spring-holding post, but is only f in. square. If 
it is more convenient to cut it from the same piece of 
steel you used for the spring-holding post, there is no 
reason why you should not do so, and make it the 
same size. I should say that these posts may be made 
of round rod if you like ; but if you do make them 





Electrical Things to Make 87 


of round rod, you will have to file a flat on the side of 
the spring-holding post to fix the spring to. 

The screw of the contact-breaker has a very fine 
thread, so that it can be set minutely. The post 
must be threaded to take this screw so that the point 
will touch the spring halfway between the near faces 
of the spring-holding post and the armature. Where 
the spring and the screw-point meet, you must 
solder to the spring a small square or circle of platinum. 
Most likely you can get what you want fairly cheaply 
from a motor-car shop or garage where they do repairs. 
You will be well advised to buy the screw with the 
big knurled head from an electrical shop. It should 
have a platinum point. Get the people you buy it 
from to thread your post to take the screw, having 
decided exactly where the hole is to come. 

The condenser is made of 120 sheets of tinfoil 
7 in. by 5J in. You will want 125 sheets of thin 
waxed paper 7j in. by 5f in. To build the con¬ 
denser, place two sheets of the paper on top of one 
another on the table, and proceed to lay a sheet of tin- 
foil on it touching one end of the paper. Then put 
on another sheet of paper, and then another sheet of 
tinfoil, touching the other end. So you go on, placing 
the tinfoil alternately to the right and left until you 
have used all the foil. Lay the remains of the waxed 
paper at top and bottom, connect all the foil sheets 
at one end to one length of wire, and all those at the 
other to another length of wire. Wrapped in several 
thicknesses of waxed paper, or in a sheet of oiled silk 
and securely tied, your condenser is now ready. 

You can see by the early diagrams how to fix the 
various parts together. It will be well to cover the 





88 Something to Make 

coil itself with a layer of thin leather, or with a sheet 
of thick paper, blackened and varnished, to protect 
it and give it a good appearance. 

The only part of the fixing that is likely to cause 
you trouble is the connecting of the wires. Fig. 1, 
which you should refer to again, shows the con¬ 
nexions clearly. Make all possible connexions on the 
inside of the wood. For instance, the connexions 
for the primary coil should be in two little grooves 
on the inside of bobbin at the end away from the 
contact-breaker. Holes should be drilled right 
through the base to let them through, and grooves 
cut on the underside of the base. One end, the 
beginning end, of the primary wire is connected to the 
terminal marked Tj on Fig. 5. And similarly, grooves 
may be cut for the secondary connexions to the 
terminals shown on top of the bobbins. The wires 
from the condenser are connected to the bases of the 
posts m and n. To the base of post m is also con¬ 
nected the finishing end of the primary coils. The 
battery terminal (t 2 ) that is not connected to the 
primary coil is connected with that end of the con¬ 
denser wire that is fixed to post n. 

Now, when all your connexions are made, comes 
the great moment. Connect up a battery of six 
large-size dry cells to the battery terminals on the 
base of the coil. Most likely nothing will happen 
save a sharp click as the armature is attracted to the 
coil. You will have to adjust the knurled screw 
of the contact-breaker until the armature vibrates 
rapidly. Now switch off, or disconnect, the battery, 
and connect lengths of wire to the secondary terminals 
on top of the bobbins. Fix the free ends about an 





Electrical Things to Make 89 

inch apart, and start the coil again. A torrent 
of sparks should leap between the ends of the wire. 
Now adjust the screw of the contact-breaker again 
until you get the best and fiercest spark, and draw 
the wires away from one another until you are 
getting a spark an inch and a half long or more. Be 
very careful not to touch the wires whilst the coil is 
working, or you will get a severe shock from the 
high-pressure current. You may find it necessary to 
increase your battery power to get the maximum 
effect out of the coil. In this case try first one and 
then two more cells. 

As I told you at the beginning of this article, 
you will have to buy your tube. You cannot possibly 
make it. Fig. 6 shows the very simplest form of what 
is known as a “ focus tube.” It is a thin glass bulb— 
you must handle it carefully—with the air pumped 
out of it so strongly that there remains inside less than 
one-twenty-millionth part of an atmosphere. Inside 
are fixed two mirrors of metal. One, you will see by 
the drawing, is concave. This is called the cathode, 
and is made of aluminium. The other is fiat, and made 
of platinum. It is called the anti-cathode or “ anode.” 
When you pass a spark from your coil through this 
tube a shower of radiant particles leaps from the 
convex cathode and bombards the anode. From the 
anode the X-rays are generated, and deflected out¬ 
wards through the walls of the tube. 

A full-size new tube would cost you several 
pounds; but you don’t need a new one, or a very 
big one. Go to your local library, and look 
through the numerous advertisement columns in any 
of the good electrical trade papers. You will see 






90. Something to Make 

there the names of firms who supply second-hand 
electrical goods. From one of these firms you should 
be able to purchase a small tube, say with a three-inch 
bulb, for about ten shillings. This will be quite good 
enough to start with, and you can take photographs 
of your hand and of the bones of small animals. 

The stand for your tube is easily made from wood. 
Fig. 7 shows you the shape of it. The base is a piece of 
wood a foot square. The uprights should be about 
two inches wide and eight inches high. I have 
shown the brackets as made of wood. They could 
quite as well be made of metal if you have any 
suitable pieces. The stand must be firm. In the 
brackets should be cut notches to hold your tube. 

To take X-ray photographs you should place 
your tube in the holder with the platinum anode 
pointing downwards. On the base-board place an 
ordinary “ rapid ” photographic plate wrapped in 
light-proof paper. This paper is to keep out the 
daylight; the X-rays will go clean through it. The 
sensitive side of the plate should be uppermost. 
On top of it, between the tube and the plate, place 
whatever it is you want to photograph. A purse 
containing coins, or a small bird or animal, such as a 
mouse—a dead one, of course, for you would not be 
able to keep a live one still long enough. Switch 
on your battery and start the coil. If you have con¬ 
nected the right ends of the secondary coil to the anode 
and cathode wires of the tube, the tube should appear 
to be filled with a beautiful green colour. If it isn’t, 
change the wires over, and the colour will appear. 
The colour should be brightest round the concave 
plate. To get a good clear photograph the exposure 






Electrical Things to Make 91 

to the rays should be for about a minute or a minute 
and a half for a small object. A human hand will most 
likely take longer. It depends on the power of your 
coil and the size and condition of your tube. A few 
trials will soon tell you the right amount of exposure 
to give. The plate must be developed in the ordinary 
way. 

Much work with large X-ray tubes is dangerous to 
health, but you need fear no evil results from the 
occasional use of small tubes. 

Don’t keep sensitized photo plates in the room 
when the tube is working unless they are in a lead-lined 
box, with a good thickness, say half an inch, of lead 
round them. If you do have the plates in the room 
without this covering they will soon be spoiled. 







A FLUOROSCOPE 


T HE fluoroscope is quite a simple apparatus by 
which you can examine objects by the rays 
of the X-ray apparatus described in the previous 
chapter. 

An old half-plate camera can be made to serve 
quite well. If you haven’t got this, get a box of 
light wood about a foot square, and take out the 
two ends. Strengthen the interior so that it will 
remain square, and tack over one end some light¬ 
proof cloth. The black velveteen that photographers 
use for focusing is what you want. You need it 
for the same purpose, to keep out the light whilst 
you are using the fluoroscope. If you like you can 
fix a handle to the underside of the box to hold it 
by. A length of broom handle about a foot long 
will serve, or the handle of an old chisel. 

To the other end of the box you must fix a 
fluorescent screen. This is another of the things 
you must buy. It will be a sheet of stout paper 
covered with certain chemicals. These chemicals 
are actually a compound called “ Platinum barium- 
cyanide.” You can fix the screen to a wooden 
frame that fits in the end of the box. 

To use the fluoroscope fix the black cloth over 
your head, and hold the object you wish to examine 
between the rays and the screen, being careful not 
to tear the paper. The screen should appear a 
lovely green colour. If you are looking at your hand 
by the rays, you will see all the bones distinctly. 

92 


HOW TO MAKE A HOME TELEPHONE 


PHE space here available does not permit of a 
dissertation on the theory of the telephone, but 
those who wish to master its principles with the 
briefest possible study should read Cassell’s “ Work ” 
Handbook on the subject. There are one or two 
points, however, which must be explained before a 
fair start can be made. Modern instruments are 
roughly divisible into two distinct classes : (1) The 
long-distance telephone, which works with high- 
tension alternating currents derived from an induction 
coil; and (2) The simple short-distance, or domestic, 
telephone in which no induction coil is used, speech 
being transmitted by low-tension direct current 
supplied by a few battery cells. It is with this latter 
class that we are concerned. 

The two essential units of every telephone are 
(1) the transmitter (or microphone), and (2) the 
receiver, all other parts being subordinate to these. 
Although in many instances the small circular casings 
of these two units may superficially resemble one 
another closely, their internal arrangements are 
wholly distinct both materially and in principle, 
the transmitter being little more than a box enclosing 
pieces of solid carbon and some granular carbon, 
while the receiver is a delicate, if simple, magneto¬ 
electric device. In some telephone sets the trans¬ 
mitter and the receiver are separately mounted, the 
former as a fixture to the main apparatus, and the 
latter as a loose attachment thereto, electrical con- 

93 


94 Something to Make 

nexion being maintained by means of a cord 
enclosing the conductors. In other patterns the 
transmitter and receiver are united to form the 
so-called “ hand combination ” instrument which is 
familiar to everyone. 

A telephone receiver contains a magnet wound 
with fine-gauge insulated copper wire. Now a word 
or two on magnets. Two distinct kinds exist—one is 
known as the permanent magnet, and the other as 
the electro-magnet. The familiar nursery toy is a 
permanent magnet, it is made of hardened tungsten 
steel, which retains the magnetism first imparted to 
it for an indefinite time, only very gradually weaken¬ 
ing with age. The electro-magnet is made of soft 
iron ; it becomes magnetic only when a current of 
electricity is caused to circulate through coils of 
insulated wire wound upon it; when the electric 
current ceases to circulate round it, nearly all trace 
of magnetism vanishes instantly from the iron (this 
is the kind of magnet used in electric bells). In 
almost universal practice the magnets used in tele¬ 
phone receivers are hard-steel permanent magnets, 
and it is very generally assumed—even by pro¬ 
fessional electricians—that soft-iron electro-magnets 
are useless for the purpose. Such, however, is not 
the case, and for short-distance domestic telephones 
soft-iron receiver magnets are found to answer 
tolerably well. Their adoption so very much sim¬ 
plifies home construction that their employment is 
embodied in the present scheme. 

Fig. 1 is a plan and half-section of a practical 
telephone receiver, and Fig. 2 shows a granular 
transmitter (or microphone) in the same manner. 






Electrical Things to Make 


95 


Both have been spe¬ 
cially designed for these 
pages, and, despite the 
homely materials se¬ 
lected and the ’prentice 
methods of construc¬ 
tion devised, no doubt 
of their efficient work¬ 
ing need trouble the 
would-be maker if only 
he will follow the in¬ 
structions implicitly 
and work with care. 

Excepting only the 
bobbin of wire b , Fig. 1, 
and the carbon button c, 

Fig. 2, both instruments 
(including the electro¬ 
magnet m, Fig. 1) are built up of circular tin boxes and 
scrap tinplate. Let Fig. 1 be first described. The plan 
(above) shows the interior of the receiver with its cover 
removed, but the latter appears in position in the 
half-section (below), t is a round shallow tin 2j in. 
to 2j in. in diameter by § in. to 1 in. deep, including 
the lid, which is seen at l in the section, with a second 
lid l 1 expanded to fit over it (working details will 
be given later), m is an electro-magnet of unusual 
form, having three limbs of square cross-section 
springing from the yoke. The bobbin b , which has 
a squared core tube, fits upon the magnet’s central 
limb m 1 ; this bobbin is evenly wound with a con¬ 
tinuous length of fine-gauge insulated copper wire, 
many layers deep, as suggested by the latticed lines 






















































































g6 Something to Make 

in the section ; the two ends of this winding are 
connected (see plan) to the ends of the two conductors 
w of the twin flexible cord /, which is brought into 
the casing t through a small metal tube t soldered 
into t. The magnet m is secured centrally to the 
bottom of the casing t, either by soldering or by a 
layer of cement x, or both. The lid l, when forced 
firmly on to the casing t, almost, but not quite , 
touches the flattened tops of the three limbs of the 
magnet m. The upper lid l 1 is forced a short dis¬ 
tance on to l ; l 1 has a f-in. diameter hole cut in 
its centre, and its surface is curved inwards, as shown ; 
the rim of id’s aperture is thus brought close to the 
top surface of l without bearing upon it, and an an¬ 
nular air space is left between l and L 1 , forming a 
resonance chamber or sound box; the hollowed 
surface of l 1 fits conveniently against the ear when 
the receiver is in use. 

Turning now to Fig. 2 a similar tin box t is seen 
similarly fitted with two lids l and l 1 , but in this 
case l 1 is driven a little further on to l, the surface 
of the top lid l 1 is left flat, and a tinplate mouth¬ 
piece or funnel f is soldered into its f-in. diameter 
central hole. A piece of flat wood (shown grained) 
is shaped to fit into the bottom of the box t ; the 
wood is J in. thick, and can be secured in place with 
sealing wax or pitch by first warming the bottom of 
the box. Centrally in the box the carbon button 
c is attached to the wooden strip by means of a single 
screw, the point of which must on no account touch 
the metal of the box. Electrical connexion with the 
button c is made by the wire w 1 , which is soldered 
to a tinplate disc, or washer, on which the button is 





Electrical Things to Make 97 


firmly seated under the pressure of its screw. The 
other wire of the twin flexible conductor, which 
enters by the tube t , is soldered to the side of the tin 
box t at any convenient point, as at x in the plan. 
When the lower lid l of the box T is pressed on as 
far as it will go, there must remain a space between 
its under surface and the face of the carbon button 
c of about J in. or less, but the lid must not touch 
the button. It will be observed, both in the plan 
and the half-section, that the top surface of the 
button c is grooved by a couple of annular rings, the 
use of which will be explained later. 

The shallow space between l and c is occupied 
by a small quantity of finely granulated carbon, 
shown in the cross-section by black dots. To keep 
these loose grains in 
position and prevent 
their escape into the 
body of the box many 
devices have been 
adopted, the idea being 
to confine them within 
the required area with¬ 
out forming a too rigid 
connexion between l 
and c. A cotton-wool 
“ nest ” formed round 
the button and pressing 
lightly against the lid 
serves very well. In the 
illustration (Fig. 2) this 
“ nest ” is suggested 
(rather unconvincingly) Fig. 2 






L'- 

u niunu i -rrrrjzq 

L- 7 yr—-m 

k/* *f|* * 1 / 

— -V 

1-r ” 

tgi 


..*T. 



1 lw 

tjl — - 



G 



































































98 Something to Make 

at n. In this case it is formed by a length of dry, 
soft lampwick (such as is used for colza and heavy 
oils). The wick is wrapped two or three times round 
the button c, and tied with thread ; the fluffy margin 
left projecting J in. or so above the face of c is clipped 
evenly and spread outwards, so that when the lid l 
is forced on to the box t the wick wrapper will open 
out, pressing lightly against l all round and forming 
a secure but yielding nest from which the fine carbon 
grains cannot escape. In the plan drawing the 
grains are omitted to show the grooved button face 
c, and the out-turned brim of the nest n appears as 
an unshaded white ring. 

Now for the working details : Circular tin boxes 
and lids (t and l) abound in every household which 
does not consign them to the dustbin. They con¬ 
tain (or have contained) tooth powder, blacking, 
metal polish, and such-like commodities ; they vary 
in size, the smaller ones being 2| in. in diameter by 
about f in. deep, which are the best dimensions for 
our purpose. As a whole these tins are beautifully 
made, their seamless bodies and lids fitting perfectly 
together. But the substance of the sheet from which 
they are pressed differs considerably as batch after 
batch flows into the market. Our selection must be 
made from the thinnest metal; the bodies of the boxes 
may be stout, but the under lids (l) should be as 
thin as can be found ; the upper lids (l 1 ) need not 
be so. The FAicryl tooth powder tin of the 7|d. size 
is often found to have a lid of exceptionally thin 
metal, perfectly fitted to the body and quite flat at 
the top, suiting the present requirements admirably. 
The scaled drawings, Figs. 1 and 2, are made from 







Electrical Things to Make 99 



a Eucryl box, but doubtless precisely 
similar tins are used for other goods. 
The reason that the lid L must be 
of thin substance is because it is used 
as the vibrating diaphragm in both 
instruments, by means of which 
the sound-waves of speech are collected, transmitted 
and reproduced. Every care must be taken to 
maintain the surface of the L-lid perfectly flat; 
bruises, dints, or distortions will quite unfit it 
for its purpose. The selection being made (one 
box and two lids for each instrument), the first 
operation is to remove every trace of the enamel 
from the surfaces, leaving the metal perfectly 
clean and bright. This can be done most speedily 
and completely by means of caustic soda or caustic 
potash ; a strong solution of either in a little cold 
water, applied with a tuft of flannel tied to a stick, 
will dissolve the hardest enamel paint in a few 
minutes, after which the tins can be rinsed and dried. 
(Do not touch caustic alkali with the fingers, or it 
will cause sores, and do 
not spill it on your 
clothing, or elsewhere, 
because it corrodes and 
destroys many sub¬ 
stances besides enamel 
paint.) Failing caustic 
soda, a boiling solution 
of washing soda will 
remove the enamel 
more slowly, but vig¬ 
orous scrubbing will be Fig. 4 

























ioo Something to Make 

needed. Do not scrape off the paint with a knife, 
because the tin coating of the thin sheet iron will be 
scratched, and the iron itself may be scored and 
distorted. When all are cleaned the lids l 1 must be 
expanded to push on to lids l, which is very easily 
done by gently beating the rim or flange of the lid 
all round with a light hammer, the rim being sup¬ 
ported meanwhile on any rounded iron object, such 
as the head of a larger hammer, as in Fig. 3. Very 
gentle blows distributed evenly and equally all 
round the flange will slowly expand the metal, and 
after the lid has been revolved three or four times 
while several hundred light taps are delivered, the 
flange will be enlarged sufficiently to press on to the 
lower lid as far as required. The §-in. central hole 
in l 1 can be cut out with a brace and sweep-bit of 
that diameter without damaging the tool; but 
failing this a circle may be scribed with compasses, 
and then cut out with a pair of old nail scissors. 
This will slightly distort the lid, but the thin metal 
can be pressed flat again, and the hole trimmed 
circular to the scribed line with a rat-tail file. For 
the transmitter (Fig. 2) the lid is left flat, but the 
receiver lid (l 1 , Fig. 1) is hollowed inwards by placing 
it over a hollow cavity gouged in a piece of wood laid 
on the bench, and pressing, rubbing and smoothing-in 
the metal round the orifice with the rounded end of 
any hardwood tool handle. Hammering is un¬ 
necessary in this case ; pressure and rubbing pro¬ 
duces a neater job. The conical mouthpiece of the 
transmitter (f, Fig 2), measures If in. in diameter 
across the flare and tapers at the angle of 90° to its 
apex, which fits into the f-in. diameter hole in the 






Electrical Things to Make ioi 

lid l 1 ; its height is f-in. This must be cut out of 
thin tinplate according to the plan seen at Fig. 4, 
which almost speaks for itself. A 2j-in. circle is 
scribpd outside a f-in. circle, then diagonals are 
scribed and one quadrant of the larger circle is cut 
out, less a f-in. parallel margin left as a lap to 
form a soldered seam when the metal is shaped to 
form a funnel. The seam being evenly lapped and 
soldered, and the cone pressed, rolled and rubbed to 
shape on the bench by means of a ruler or smooth 
tool handle, the finished mouthpiece will be true to 
pattern (f, Fig. 2), the J-in. circle in the plan (Fig. 4) 
having “ shrunk ” to a f-in. aperture and the 2f-in. 
circle to a lf-in. flare. All that remains is to solder 
F neatly into l 1 as at Fig. 2. Before dismissing 
Fig. 4 let it be observed that the solid lines represent 
the pattern to be cut out, and the dotted or broken 
ones are “ construction ” lines, without which the 
cone plan cannot be accurately drawn on the tin¬ 
plate. 

Fig. 5 is a fully dimensioned plan of one sheet 
of the laminated magnet (shown in position within 
the receiver at Fig. 1). A solid soft-iron magnet 
sawn or filed from f-in. by J-in. strip-rod would 
serve the purpose, but it would not be nearly so 
efficient as one made up of numerous thin sheets of 
iron pressed closely together, because a laminated 
electro-magnet accepts and rejects magnetism, as it 
were, more promptly than does a solid one, and that 
is very important in this case. The laminae used by 
electricians for dynamo armatures, transformers, 
etc., are made from a special quality of soft sheet 
iron without any coating of tin. But tinned iron 






102 Something to Make 

will serve our purpose admirably. Nestle’s milk 
tins are of fine Swedish iron very lightly tinned ; 
when opened out and rolled flat on the bench better 
material could not be wished for. It will be seen 
by Fig. 5 that this three-limb magnet is 1J in. long, 
| in. deep, and J in. thick—to obtain which thickness 
about twenty laminae of average milk-tin are re¬ 
quired. Having thoroughly washed, dried and flat- 
rolled a sufficient quantity of tinplate, mark it 
accurately and cut into strips £ in. wide ; roll them 
flat, and then, with a rule, dividers, set-square and 
scribing-point, mark out, cut out, file up and finish 
accurately one lamination exactly to the measure¬ 
ments given in Fig. 5. This will serve as a template, 
or master pattern, from which the nineteen remaining 
laminae can be quickly marked out for cutting. 

A bradawl ground to a smoothly rounded point 
makes a serviceable scriber with which the thin 
metal may be scored deeply to the pattern lines 
when laid flat on the bench, and the scored lines 
will much assist cutting out. Cutting must be done 
systematically. The patterns, being marked out in 
line on each f-in. strip of tinplate (see Fig. 5), should 
not at first be cut into lengths, but left in the strip 
while the f-in. by J-in. spaces are removed by the 
three cuts x and y. Proceed as follows : Lay the 
marked strip flat on the surface of a laundry iron 
(the handle of which is nipped between the knees of 
the seated workman). This makes a convenient 
anvil. 

Next take a light mallet, or hammer, and a 
carpenter’s ordinary wood chisel f in. wide ; adjust 
the chisel edge fair and square on the scored line x , 








Electrical Things to Make 103 

between the ends of the two lines ?/, and apply a 
sharp tap with the mallet. This cut will not go 
through the tinplate, but it will be deep enough. 
Cut all the x lines similarly. (The chisel will not be 
seriously damaged, although blunted, and the edge 
may need attention before its unusual metal work 
is done, after which a quarter of an hour’s resetting 
will restore it for its legitimate work on wood.) The 
x lines being cut half through, the two y lines are cut 
neatly down to the x lines with a pair of strong nail 
scissors, when the f-in. by J-in. pieces can be gently 
broken out, leaving the strip “ battlemented ” with 
a row of turrets. Roll it flat, cut the patterns apart 
truly on their dividing lines, roll them all severally 
again, trim the burrs from their faces with a file, 
and repeat the process until a sufficient number of 
laminae are accumulated to bulk to a thickness of 
J in. when pressed together. 

Another word on milk tins. After washing clean 
in boiling water, the tops and bottoms can be knocked 
off by heating (not too strongly) over a gas ring ; the 
folded seam of the body must then be cut away 
altogether, which will leave unblemished metal 
enough for three f-in. strips 9 in. long ; each strip 
will accommodate six patterns in line (Fig. 5), and 
so, of course, three milk tins will cut up into 54 
laminae, more than enough to make the electro¬ 
magnets for two receivers (Fig. 1). 

Needless to say, the thicker the tinplate the fewer 
laminae required, but this thin sheet is tractable to 
work, to flatten and to cut with ordinary scissors, so 
its use is warranted despite the additional leaf- 
number requisite to produce a given bulk. Besides 







104 Something to Make 

this, numerous laminations are desirable in an electro¬ 
magnet. The assemblage of twenty or more cut 
sheets to form a solid and shapely compound block 
demands care and the provision of a special accessory 
in the form of a little screw clamp devised to compress 
the sheets and hold them firmly while, by heating, 
they are fused together (by their own adherent tin) 
into a solid block. If the clamp to be described is 
beyond the skill and facilities of the reader, any 
ironmonger or cycle agent will make it to order for 
a trifle. It consists of two pieces of strip iron £ in. 
wide by lj in. long by J in. to £ in. thick, having 
two £-in. holes drilled through them centrally at 
| in. apart. A dimensioned plan of one plate appears 
at Fig. 6 ; a and b is a side view of the clamp complete 
with the magnet in its grip, as suggested by the pole 
ends m. The two nutted screw bolts are stock goods 
procurable anywhere ; they may be 1 in. long and 
T 3 ^ in. in diameter. 

Returning to the magnet laminae : First true all 
their base lines, individually, by rubbing lengthwise 
on a fine-cut file laid flat on the bench, then finally 
smooth away all face burrs and carefully flatten every 
leaf; assemble the requisite number, poles up and 
base down, on a level surface, tap the ends of the pack 
deftly to bring all the poles and slots into alignment, 
slip the clamp over them, with its bolts midway in 
the slots and its ends fair with the sheets, and bolt 
firmly together ready for fusing up (Fig. 6). 

The interfusion of the tinned-iron sheets is merely 
a soft soldering process known to the trade as “ sweat¬ 
ing-in,” an expressive term which describes any 
soldering job for which a soldering-bit is not required. 





Electrical Things to Make 105 


*/4 

!■ 


y-* 

3/s 


/4 


-y- 

3/8 


% 


*//y 


'/4 


% 


twc 



sheets 


Fig. 5 


The complete success 
or partial failure of a 
sweated joint depends 
(a) on the perfect clean¬ 
ness of all surfaces which 
can be united in this 
way, and ( b ) on the 
lavish application of the correct flux, and (c) on suffi¬ 
cient but not excessive heat, maintained long enough 
to “ soak ” the joint. Unless otherwise specified the 
flux referred to in these articles is zinc chloride , to 
the exclusion of all others. This is the liquor fami¬ 
liarly miscalled by workmen “ killed spirit of salt,” 
“ killed spirits,” “ spirit,” etc. Make it for yourself 
with an understanding mind. Hydrochloric acid, 
muriatic acid, and spirit of salt are one and the same 
thing, but the last named is an oil shop commodity 
of much impurity. Procure muriatic acid (com¬ 
mercial quality) from a druggist. 

Place the acid in a stoneware jar out of doors, 
and drop into it clean cuttings of sheet zinc— 
one or two at a time at first, then add more as the 
violence of the action modifies, otherwise the bubbling 
acid will froth over and be wasted. 

Do not inhale the hydrogen fumes, 
or approach a light near to the 
jar (the fumes would half choke 
you, and the light would explode 
the gas). As the action quietens 
dump in plenty of cut-up zinc, 
cover the jar loosely with a tile, 
or square of glass, and leave 
for twelve hours for all trace of Fig. 6 


NS'' 
> ' s 


v V 1 




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a 



V N 

N N N N 


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N N S 

**N 

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1 ' 


rp~ 

|777j 


l ! 


\rn\ 

\ \ 
S « 

\ 


' v\' . 


I 

i!i: 

K\N i , Hill 

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io6 


Something to Make 


action to cease and the fluid to settle. Then care¬ 
fully decant off the clear, colourless, heavy liquor 
from the remaining metal and black dross into a 
clean wide-mouthed bottle. Keep corked, and apply 
the zinc-chloride-flux thus produced without dilution. 

A “ brush ” for dipping may be made by beating 
loose the fibres of a piece of cane at one end, and 
soaking the other in wax to prevent the fluid creep¬ 
ing upward. Finished soldered work should be 
washed thoroughly free from flux immediately on 
its cooling, first in plain water, then in hot water 
and soda, rinsed and dried. 

(To save you disappointment, the above digression 
had to be made. Take the advice of an expert and 
always eschew the use of all ready-made soldering 
fluxes for serious work.) 

Before clamping up the magnet, as in Fig. 6, it 
is advisable to “ soil ” the black-iron faces of the 
clamp with a smear of glue and lamp-black (or soot) 
to make sure that no solder will adhere when fusing 
up the leaves. The clamp being secured, proceed 
systematically as follows : Twist a strong wire round 
the clamp to form a handle ; turn it about over an 
atmospheric gas-ring until it becomes barely hissing- 
hot ; then remove from the flame and apply zinc- 
chloride-flux liberally to all the exposed edges of the 
magnet. While this is being deliberately done, the 
work is cooling off, of course, and observation will 
show that some of the flux-liquor is being sucked in 
between the leaves—which is as it should be ; warm 
up a second time and repeat the fluxing ; then heat 
strongly until, here and there, the tin coating is seen 
to be in fusion. At this point do not overheat , but 







Electrical Things to Make 


107 


maintain the melting-heat. Dip a strip of thin 
blow-pipe solder into the flux and with it lightly 
touch over the magnet edges all round, melting a 
little solder on to each; then brush the molten 
metal with the flux-stick, and observe that it flushes 
and soaks in among the leaves. Heat again, strongly 
but moderately, and allow to cool for some time 
after the solder is well set. 

Finally, quench in clean water, swilling away 
most of the flux before removing all trace of it in 
hot water and soda ; rinse and dry. Slack off the 
screws and the twenty-layer magnet will drop out 
as a solid block. Finish square and true to dimen¬ 
sions by filing on all sides, being particular to make 
the pole tops level and the middle limb smooth and 
shapely for the bobbin tube. The clamp will prove 
very useful when filing up, acting as a vice to grip 
the magnet in several positions, with its base, pole 
tops or ends just projecting sufficiently for filing 
square, the same being done while the slots are trued. 
The magnet being finished, next comes the bobbin. 
This is seen in position in Fig. 1, and separately, in 
half-section, at b, Fig. 7 ; a , of the same figure, 
being a dimensioned plan of one of its discs or cheeks. 
These are f-in. in diameter, with a T %-in. squared 
hole in the centre to fit a square core tube of J-in. 
square bore, to push on to the middle limb of the 
magnet. The cheeks need not be circular, as shown, 
but square or octagonal if preferred. They are made 
of very thin tough fretwood ; the thinner the better, 
because more space between them will be left for 
the fine-wire winding. The tube is made of several 
thicknesses of tough notepaper rolled on a square 








108 Something to Make 

former and glued together. The magnet limbs m 
(Figs. 1, 5 and 6) are £ in. square and J in. long to 
the slot bottoms ; therefore, the bobbin must be a 
shade less than £ in. deep to allow the pole top of 
m to project above it (see the section, Fig. 1). Plane 
a strip of tough wood to exactly £ in. square ; glass- 
paper it and rub with wax to make it damp-proof 
and quite smooth. This is the tube-former. Cut a 
strip of writing-paper, say £ in. wide and about 
3£ in. long ; wrap this tightly round the square stick 
three layers deep on all sides and cut off evenly ; 
unroll again and pencil-mark the meeting-point of 
the first lap ; brush the remainder of the strip with 
thin, hot glue ; rub the former-stick with french 
chalk ; roll on the unglued inner layer of the paper 
strip and then the glued remainder, very tightly, 
rubbing down each facet closely as the wrapping 
proceeds. Put aside to set for half an hour, after 
which pull out the former-stick and dry off the 
square tube in a warm, airy situation. Having 
drilled round holes £ in. in diameter in the two 
bobbin cheeks, square them neatly with a fretwork 
file to a size that will allow them to be stiffly pushed 
on to the paper tube, the latter having been tem¬ 
porarily replaced on the former-stick. 

Treat the tube ends and the holes in the cheeks 
with hot glue, and push on the cheeks, setting them 
square with each other, with their outer faces a little 
less than J in. apart, say in. (Fig. 7, b). Dry off 
thoroughly for twelve hours, and then cut off the 
superfluous length of tube ends flush with the cheek 
faces, using a sharp knife or wood-chisel, while the 
former-stick remains in the tube. 






Electrical Things to Make 109 

Remove the finished bobbin from the 
stick and stand it in a cool oven for one 
hour to drive off moisture; then im¬ 
merse it in melted paraffin wax, while 
still warm, for a few minutes ; remove 
and polish with a dry cloth. Cut from 
thick drawing-paper or brown paper a 
disc of the same diameter as the bobbin 
cheeks, with a square central aperture to 
fit the tube ; strip through from rim to 
centre to permit the disc, when twisted, to be slipped 
on to the bobbin. Dry and wax-saturate this disc (or 
loose cheek), the use of which will appear presently. 
If very evenly wound, the bobbin will hold about 
1 oz. of wire when filled nearly to the rims of the 
flanges. 

Hand-winding with fine wire cannot be properly 
done, so a small windlass must be knocked up of 
three bits of cigar-box wood, bradded and glued 
together. This is seen at Fig. 8 (half-scale to other 
figs). The squared former-stick will serve as an 
axle if its ends be rounded off as shown, a little 
wooden crank-handle being glued on to one of them. 
The tops of the two uprights are nicked for the axle 
ends to revolve in, and the latter is kept in place by 
two wire staples, that on the crank side being stiffly 
removable for mounting and dismounting the axle 
as required. 

The bobbin in half-section is seen 
in dotted outline, ready for winding 
when the toy windlass is fastened 
to the bench by one woodscrew. The 
store bobbin (on which the wire is Fi & 8 




Fig. 7 







































no Something to Make 

purchased) must be mounted- on a bent-wire “ horse,” 
driven into two holes in the bench at a convenient 
point. The wire is guided on to the magnet bobbin 
with the left hand, and the windlass turned with the 
right hand, over and away from the worker. One 
ounce of No. 34 gauge double silk-covered copper wire 
is required. (Cotton-covered wire will do.) Enamel- 
insulated wire may be substituted for silk-covered 
if greater care is used in handling than is necessary 
with double silk. No. 34 wire is, however, relatively 
coarse and strong for telephone work, and should 
prove manageable by any average fellow of twelve 
years and upwards. 

Younger, or exceptionally thumby, electricians 
should try to enlist the kind services of a sister (or 
someone else’s sister), because fine-wire magnet 
winding is at once delicate and monotonous work, 
and girls are much defter and more patient than the 
best of us. If she can be interested, then you may 
be sure that the following instructions will be per¬ 
fectly carried out, for, “ If she will, she will! you 
may depend on’t.” 

Assuming that double silk-covered wire is used, 
dry it by warming the reel for some hours near to 
a fire, or placing it in a cool oven for half an hour ; 
do not over-heat—scorching will ruin the insulation. 
The wire is about as thick as stout thread, but not 
nearly so strong ; it must be wound on the bobbin 
as evenly as cotton is wound on a reel—without 
spaces, without heaping up. Coils at the ends of 
one layer must not be dragged down among those 
of the previous layer. To prevent this, thin, waxed- 
paper interleaves (one thickness only) are rolled and 






Electrical Things to Make m 

smoothed down upon every completed layer for the 
succeeding layer to rest upon, wound evenly in 
close, spaceless coils. The function of the silk (or 
enamel) insulation, of course, is to prevent the escape 
of electricity from one convolution of wire to others, 
throughout, so that current entering at one end of 
the coil is compelled to traverse the whole length of 
the wire before emerging at the other end. To fix 
the importance of this in mind, think of the fine 
covered wire, analogously, as of a slender and delicate 
hose-pipe of great length, in which there must not 
be the slightest leak, kink, or strangulation from end 
to end. Now, having screwed the windlass to the 
bench, and fixed the wire “ horse ” somewhere con¬ 
veniently on your left—with its store reel ready to 
revolve and pay off its dried wire without check— 
place a lighted candle or spirit-lamp to the right of 
the windlass, within reach, along with a narrow- 
bladed screwdriver (or similar tool), some strips of 
thin, dry paper cut the exact width of the wire-space 
between the bobbin cheeks, and some loose scraps of 
paraffin-wax. Draw the wire from the store reel and 
attach it to the inner face of the bobbin’s left cheek 
with a little wax, applied with the screwdriver blade 
warmed in the candle-flame, leaving a few inches of 
the wire-end loose for connexion. Coil this loosely 
round the axle, temporarily, to keep it out of the 
way. Next slip on the loose disc or cheek of thick, 
waxed paper, previously made, and “ cement ” it 
closely to the bobbin cheek with the warmed blade, 
thus enclosing the emergent inner end of the winding 
between the cheek and the cemented-on disc, 
efficiently insulating it from contact with succeeding 






ii2 Something to Make 

layers. Now wind on the first layer of wire closely 
and evenly, turning the crank steadily and never 
pulling too hard on the wire. On reaching the right- 
hand cheek cease winding, hold the wire gently 
to prevent its uncoiling, and thoroughly saturate the 
silk covering with paraffin-wax melted with the 
warmed blade. Use no excess of wax. Take a strip 
of the cut paper, attach its end to the winding with 
a touch of the blade, coil on one thickness, and tear 
off the surplus paper, smooth down, sealing the 
narrow overlaps and both ends neatly. Wind on 
the next and all the succeeding layers of wire with 
equal care, placing an interleaf between each, until 
the bobbin is filled. Tie down the finishing-end with 
silk thread close to the left cheek, on the opposite 
diameter to the starting end, and enclose the com¬ 
pleted winding in several turns of waxed paper well 
“ sleeked ” down with the warmed blade. 

Dismount the windlass, push the bobbin off the 
axle, and lay aside, temporarily, being very careful 
not to snap off the delicate wire ends. 

Now turn back to Fig. 1. The magnet m must 
be securely fixed upright and centrally in the casing 
T. This is best done by “ tack-soldering ” ; that is 
to say, not by thorough soldering or “ sweating ” 
(because that would un-sweat the whole magnet), 
but by the quick application of two or three detached 
“ tacks ” or beads of solder melted on each side of 
the seating of ?n upon t, with a brisk touch of a very 
hot and perfectly clean soldering bit, pressed down 
on the joint (just long enough to fuse and attach the 
tack-head firmly), and then promptly removed before 
any leaf of m becomes hot enough to un-sweat. (This 





Electrical Things to Make 113 




a] 


is a quick and easy job, but give it care.) The tubes 
t. Figs. 1 and 2, are of rolled tinplate with soldered 
seams. Their ends must be opened out, given a 
fused solder-tip or heading, and smoothed to prevent 
their abrasion of the covering of the flexible twin 
conductors threaded loosely through them. They 
are soldered into holes made in the rims of the casings 
t, and may be supported within them on soldered 
tin brackets if thought 
desirable. 

After fixing the mag¬ 
net and tube in the 
receiver - body T, a 
strengthening layer of 
mixed resin, wax and 
plaster of paris (melted 
and stirred together) ^ 

may be poured in the (® /h|#| 
bottom £ in. deep. See 
x in the section Fig. 1. 

This layer gives rigidity 
to the body and magnet, and concentrates the pull of 
the latter on the resilient diaphragm (or lid-surface) 
of L. This done, the bobbin b is pushed on to the 
central limb of m, the latter being slightly warmed 
if necessary ; the flexible is passed through the tube 
and secured by a wrapping of waxed cotton or 
woollen yarn knotted round it to form a plug which 
cannot be pulled backwards through the tube. The 
two conductors are then separated, \ in. of their 
insulation being stripped back and tied. The in¬ 
sulation on the ends of the fine magnet wire is simi¬ 
larly stripped back and the metal of both wire ends 





Fig. 9.—Diagrams showing 
Telephone Connexions 


H 






























ii4 Something to Make 

and flexible ends being carefully cleaned quite bright, 
one of the magnet wires is twisted on to each of the 
conductors and soldered with resin-flux only (and not 
zinc-chloride), after which the bare metal joints must 
be re-insulated with waxed silk or wool. The slack 
loops of wire-jointed conductor may then be spread 
apart on the surface of the resin and wax layer x, 
and lightly secured to it by pressing down with the 
cooled-off soldering-bit. To avoid complications the 
plan Fig. 1 does not show the detail of the soldered 
joints or the woollen boss round the flexible at the 
tube end, but w w 1 , emerging from the inner end 
of t, sufficiently explain the connexion of the twin- 
flexible / with the winding on the bobbin b. 

The diaphragm, or flat lid l, is then pushed on 
to the body t, and if all has been properly fitted the 
diaphragm should be separated from the pole tops 
of m by a space about equal to the thickness of a 
thin visiting-card and no more. It should be possible 
to feel the flat top of l just touch the pole tops when 
the middle of the diaphragm is lightly pressed down 
with the fingers, l being pushed on as far as it will 

g°. 

L is then secured to t by three “ tacks ” of solder 
equi-spaced round the rim. (For this—for the 
attachment of m to t —and for all wire-connexions, 
no other soldering-flux than powdered resin may be 
used, because corrosion soon fouls or destroys any 
soldered work which cannot be thoroughly washed 
free from other fluxes.) Finally, l 1 is pushed firmly 
on to l (it need not be soldered), and the receiver is 
ready to “ speak.” 

Before it is able to do so, however, the transmitter 







Electrical Things to Make 115 

(Fig. 2) must be finished off. All its constructional 
details have already been explained. The compressed 
carbon button c is procurable from any electrician’s 
stores for a few pence, and prepared carbon granules 
are sold by the ounce—| oz. will be enough for two 
transmitters. If thought worth while a button 
could be made from a broken battery-plate, about 
f in. thick, by chipping and afterwards grinding 
circular on a stone doorstep or household sink. 
Granules also could be prepared by grinding and 
sifting; but the carefully graded, dustless and 
burnished granules cheaply purchasable are much 
to be preferred. The flexible having been tied off 
with a waxed woollen binding, as directed in the case 
of the receiver, one conductor is soldered to the body 
(x in the plan, Fig. 2), and the other to the metal disc 
beneath the button c. The “ nest ” n must then 
be filled loosely with granules, and the lid-diaphragm 
L pushed gently down upon the yielding brim of 
the nest. When l is down as far as it will go, the 
granules must not be densely compressed in a solid 
pack ; nor, on the other hand, must they be rattling 
loose in their fabric nest. A mean between these 
two extremes must be arrived at by trial and error ; a 
small pinch of grains, more or less, makes all the 
difference, and the best possible test of the correct 
amount will be made with the instrument in actual 
use. Do not, therefore, fix l permanently on to t 
(of the transmitter) until a number of speaking-tests 
have been made. Then fix with three solder-tacks, 
as in the case of the receiver, and push on l 1 and 
its mouthpiece firmly. 

These practical instructions have been laboriously 






n6 Something to Make 

simplified to the comprehension and constructive 
capacity of our younger readers. Homely and 
costless materials have been deliberately selected, 
design and method being originated to permit their 
use, while maintaining the science. 

Connected by No. 20 or No. 22 gauge electric bell- 
wire, and energized by a flash-lamp battery, the 
transmitter will convey speech distinctly and loudly 
to the receiver over a distance of seventy-five yards 
or more when coupled up as in diagram a> Fig. 9, 
in which t is the transmitter, b is the battery, and 
r is the receiver. To speak and to hear at both ends 
of the line, two pairs of instruments, of course, are 
required. They would be connected as at b , Fig. 9, 
in which the lettering of the units is repeated. But 
the proper installation of two or more telephone 
“ stations ” involves the construction of wall-sets or 
“ rosettes,” with automatic switches, push buttons, 
call bells, etc. 






HOW TO MAKE AN ELECTRIC FIRE 

ALARM 


T HE electric fire alarm shown in Fig. 1 costs 
practically nothing to make. The wooden base 
is C in. by 3§ in., and about § in. thick. Two bent 
bearing plates are wanted, as illustrated in Fig. 2. 
These may be made in thin brass, or even cut out from 
a cocoa tin, the holes being either bored or punched 
with a hammer and nail, afterwards being filed flat. 
The finished plates measure 1 in. by \ in. 

A spiral spring is formed by winding some fairly 
stout copper wire round a pencil or penholder, as seen 
in Fig. 3, though it is better to do the coils a little 
closer. The completed spring (Fig. 4) may be If- in. 
long with a piece a left projecting for 1 in., while at 
the other end b a piece 3 in. long is left, which is bent 
over and fastened into a loop, the length being then 
about If in. 

Next, we want a piece of J-in. thick iron rod or 
wire, 3J in. long. In the actual model illustrated 
this was cut from a round meat-skewer, by means of a 
small file. The rod is passed through the spring and 
fixed to the base by screwing on the bearing plates, so 
that the rod is 1^ in. from the bottom. Fix a small 
brass screw in the base, near the short projecting end 
of the spring (a, Fig. 4), and twist the end once round 
the screw. 

Now make the bent contact plate, shown in Fig. 5, 
of thin brass or tin. This is If in. by J in., and should 
be about If in. long when bent. Having made two 

117 


118 Something to Make 

holes, screw it on at the bottom, so that the wire loop 
lies across the middle. 

The bent spring piece seen in Fig. 6 is of thin hoop 
iron, J in. wide, such as is often nailed round date 
boxes. This may be cut with old scissors, or fded 
across where required and then snapped. File all the 
sharp edges smooth. The piece should be 2f in. long 
before bending. A hole is drilled or punched, and 
it is then screwed at the top, in line with the wire loop, 
when it should project If in. in front of the base. 
Two holes are made in the base for fixing up. 

To set the alarm, a paper band (Fig. 7) is needed. 
Cut a strip of thin but strong paper 1 ft. 2 in. long and 
f in. wide. Typewriting paper is very suitable. Two 
strips may be joined if not long enough. Make a 
firmly pasted or gummed loop at each end, reducing 
the total length to 10J in. When dry, an end of the 
strip is passed through the wire loop, the latter 
lifted up till at a right angle with the base, and the 
two loops placed one by one over the bent spring at the 
top, as illustrated in Fig. 8. 

The electrical connexions are as shown in Fig. 9, 

a being the bell, b the battery 
and c the alarm device. It will, 
of course, be understood that 
these are not really close together; 
in fact, the battery and bell 
may be in a distant part of the 
house or building. A w T ire is taken 
from one terminal of the bat¬ 
tery to the bent contact plate, 
another wire from the screw con¬ 
nected with the short projection 



Fig. l 

















Electrical Things to Make 119 



of the spiral spring to one of the bell terminals, and 
a third wire from the second bell terminal to the 
second battery terminal. Well scrape the ends of 
the wire for about ljin. till the metal shows bright, 
and see that they are tightly twisted round the 
terminals and the screw. To connect with the con¬ 
tact plate, loosen a screw, pass the bared wire un¬ 
derneath and round the screw, and tighten up. 

The principle of the alarm is as follows. Directly 
the flame reaches it the paper band catches fire, breaks 
and thus lets the spring loop fall sharply on the 
bottom bent plate. Since this is a terminal contact 
is made, the current passing along the spiral spring 
to the small screw which forms the other terminal, 
and the bell therefore rings. This may be experi¬ 
mented with on a bare wall, or by laying the alarm on 















































120 Something to Make 

the table, and will be found to work instantaneously 
when a match is applied. In practical use, the alarm 
should be fixed up or placed near something in¬ 
flammable, such as curtains, a pile of papers, hung-up 
dresses, etc. When this is done, common sense will 
suggest that experimenting is out of place. 

The alarm is easily connected to an existing bell 
circuit by taking two wires from it to two points in the 
bell wiring, so as to form a shorter path or near cut, 
leaving the ordinary switch or push outside. This is 
soon worked out if the path of the wires is traced and a 
rough diagram drawn. 

When the paper band is not in position, remember 
to put a thin wooden wedge under the spring loop to 
keep it off the contact plate. 






A BURGLAR ALARM FOR WINDOW 

FASTENING 


T HE electric burglar alarm shown in Fig. 1, rings 
a bell when the window fastening is forced 
back, while an attempt to throw it out of action has 
the same effect. 

This is rendered possible by a special two-way 
switch (Fig. 2). The wooden base is about fa in. 
thick, and of the dimensions indicated. Four strips 
of brass about jfa in. thick are required, but tinned 
sheet-iron from a treacle tin will answer very well, 
and has the advantage that it can be cut with an 
old pair of scissors. Remember the edges are very 
sharp, and file them down. One piece each is wanted 
of the shape and size shown at a and b in Fig. 3, and 
two as illustrated at c. The holes are best drilled, 
but can with care be punched from both sides with 
a hammer and nail, filing the raised burr down after¬ 
wards. The projecting part of the strip a is bent 
over to a curve, as seen in Fig. 2. The four strips 
are fixed on the base with small screws, the piece a 
being left just loose enough to move sideways when 
pushed. A hole is bored 
in the base at top and 
bottom for fixing up. 

The switch is attached 
by nails or screws to the 
window frame, or else to 
the wall, at such a height 
that the middle of the 



121 























122 


Something to Make 


T 

I 

» 

» 

t 

<V> 


l 
I 
• 

A 

_ B 

Fig. 3 

base is level with the top of the lower sash. A 
piece of stout twine is passed through the hole in 
the turned-over part of the movable bar, and a 
knot made on the end farthest from the window. 
With the movable bar down, as in Fig. 1, the 
cord is now led to the window fastening, drawn 
nearly taut, and tied to a small ring which will slip 
over the bolt handle, as in Fig. 4. A piece of elastic 
about 5 in. long is next passed through the same 
hole in the movable bar, and knotted on the end 
nearest the window, a small ring being fastened to 
the other end. The elastic is stretched slightly, and 
a nail is driven in the wall, over which the second 
ring is slipped, as seen in Fig. 1. 

The principle of the alarm will now be under¬ 
stood. The middle position of the movable switch- 
bar is “ off,” but contact is made, and the bell rings, 
when it is moved either to right or left. Should a 
burglar force back the window fastening, the cord 
pulls up the switch-bar on to the right-hand contact 
and operates the alarm. If, however, he detects 
the cord, he will probably cut it, or remove the ring. 
On either being done, the elastic pulls the switch- 
bar to the left-hand contact, and the bell is started 
in spite of the would-be intruder’s caution. A short 




4 f//St 


(T| 


O 

T 

foj 

s//s 













•>» 


* 


o 

l 


V. 


c 



i 





• 

I 

O 

■S' 

% 


S/,6 

— * 





A 


/ 

o 





































Electrical Things to Make 123 

nail or pin should be driven in at b and c (Fig. 2), 
to prevent the switch-bar moving too far. 

Fig. 5 shows how to connect up the wires, A being 
the bell, b the battery and c the switch. A single 
wire is taken from one bell terminal to one battery 
terminal, and another from the second battery ter¬ 
minal to the fixed middle bar of the switch. A 
“ twin ” or double wire is then led from the second 
bell terminal, the two strands being separated just 
before reaching the switch and connected respec¬ 
tively to the two side bars. The ends of the wires 
should be scraped bare for about ljin., twisted 
tightly round the terminals, and any projecting sur¬ 
plus cut off. To attach the wire to the switch, a 
screw is loosened, the scraped wire pushed under 
the bar, pulled round the screw, and the latter 
tightened up. A flash-lamp battery answers well, 
instead of the usual and more messy Leclanche. 
When the alarm is not in use, the rings are lifted off 
the window fastening and the nail. 

Another good idea for a window alarm is shown 
by Fig. 6. This allows the fastening to be opened, 
or left open, but rings a bell when the bottom sash 
is raised. It consists simply of a bent plate of brass 
or “ tin ” screwed to the lower sash, and two strips 




Fig. 7 


Fig. 5 


Fig. 6 































i24 Something to Make 


like c in Fig. 3. The wires are connected to the 
latter, as shown, when, on pushing up the sash, the 
bent plate comes across the two strips, making con¬ 
tact. Fig. 7 illustrates the shape and size required 
for the moving plate, and Fig. 8 how it should be 
bent. The connexions, in this case, are all single 
wire, namely, from one bell terminal to one battery 
terminal, from the second battery terminal to one 
of the small strips, and from the other small strip 
to the second bell terminal. 





AN EASILY MADE ELECTRIC MOTOR 



HE small electric motor shown complete in 


-*• Fig. 1, although very simple, gives a good 
insight into the principle of more orthodox and 
larger ones. 

The wooden base is 3| in. by 2f in. by f in. thick. 
The back upright, of the dimensions shown in Fig. 2, 
is J in. thick, and is screwed to the base from under¬ 
neath. The square post (Fig. 3), J in. away from the 
back, is similarly secured. 

The magnet consists of three strips of thin sheet 
iron or “ tin,” § in. wide, two being 3f in. long and 
the third 4J in. long. Mark the centre of each, and 
make small holes, filing down the burr. Bend as in 
Fig. 4, with the longer strip outside, turning the 
ends over as in Fig. 5. The three holes should 
coincide. 

To insulate the metal from the wire, stick strips 
of gummed paper, ^ in. wide, round the upright 
portions, as at a and b (Fig. 4), taking three turns 
round each. 

The wire is No. 26 double-cotton-covered copper, 
sold on reels. The magnet requires fifty turns of 
wire each side {see Fig. 6), and several inches should 
be left free at the beginning and end. It is impor¬ 
tant to wind the two sides in opposite directions, 
as indicated by Fig. 7. When wound, screw the 
magnet diagonally across the base. 

The bottom bearing (Fig. 8) is a strip of tin. 
Make holes for screws at each end, then make a little 


125 


126 Something to Make 

indentation in the centre, by holding a small nail 
upright and tapping lightly with the hammer. To 
insulate the strip from the magnet, stick three turns 
of gummed paper, 1 in. wide, as at a and b, leaving 
j 3 g- in. clear in the middle. The under side, below 
the bare part, also needs covering by three narrow 
strips across the other two. Screw the strip over the 
magnet, parallel with the front of the baseboard, 
and with the indentation just above the screw in 
the middle. 

The top bearing (Fig. 9) is a strip of stiff but 
springy brass. Make a hole for a screw, but do not 
fix it yet. 

The armature, or rotating portion, is of hoop iron 
off a box, cut as in Fig. 10, flattened and filed bright. 
A hole is drilled or punched in the middle for the 
spindle, which may be a stout needle or large pin, 
with the head cut off and filed to a point. It should 
be about If in. long. 

From a round penholder, about £ in. in diameter, 
cut a piece ^ in. long (Fig. 11), and make a central 
hole lengthways, which is best done from both ends. 
It should be a tight fit on the spindle. Push the 
piece on the spindle with the armature above, insert 

the bottom point in the 
indentation in the lower 
bearing, and shift the arma¬ 
ture till a little less than J in. 
away from the top, or poles, 
of the magnet. Then secure 
the armature to the wooden 
cylinder in this position with 
a touch of elastic glue. 

















Electrical Things to Make 127 



Fig- 2 



Fig. 6 





Fig. 13 Fig. 10 


j>-- - J'/a" - - - - -i 

o 

u= 

a 


o 


Fig. 12 


Fig. 8 


N 


J 


fc> - - - 


- 2 •»/♦" - 
Fig. 9 


-- 




Now screw the top bearing to the back support, 
hold the spindle upright in the bottom bearing, and 
mark on the upper bearing where the spindle should 
touch. Remove the upper bearing, and make a 
corresponding indentation to that below. Replace 
it, and test if the armature will spin freely when 
inserted. 

For the commutator, cut a piece of § in. diameter 
wooden curtain-rod, \ in. long. Make two nicks 
on the end exactly opposite each other, as in Fig. 12 ; 
mark down the side to obtain two similar points at 
the other end, and cut two nicks there also. Make 
a hole through the centre to fit the spindle tightly, 
and push the piece on, but not far down. Scrape 

























































128 Something to Make 

the covering off a few inches of copper wire and rub 
bright with glasspaper. Twist the middle of the 
wire once round the spindle, bring it up the two sides 
of the cylinder, resting in the nicks, and twist tightly 
together at the top, as in Fig. 13. Cut off the sur¬ 
plus, and push the commutator down against the 
armature, so that the wires point towards the ends 
of the latter, as in Fig. 14. 

Having seen that the armature still spins all right, 
the free end of wire from the left of the magnet is 
taken to the square post, and secured at the top by a 
piece of tin (Fig. 15), having a hole for screwing down. 
About 1 \ in. of the end of the wire should have been 
scraped bright, to form the “ brush,” and is bent 
so as to touch lightly on one of the commutator wires 
when the armature is in the position shown in Fig. 1. 

The free wire at the right of the magnet is scraped 
bare and twisted round a brass screw driven half¬ 
way in the base to serve as a terminal. Lastly, a 
piece of wire is scraped at both ends, one being 
slipped under the upper bearing and screwed down, 
while the other is twisted round a second terminal 
screw in the base. 

The motor may be driven by two dry cells con¬ 
nected in series—that is, the plus terminal of one 
battery to the minus terminal of the other, the 
remaining two battery terminals being connected by 
wires to the terminal screws on the motor baseboard. 
On giving the armature a slight push, the motor will 
begin to work at a good speed, tiny sparks being 
noticed where the brush touches the commutator. 






Section II 

MECHANICAL THINGS TO MAKE 


A QUARTER-PLATE CAMERA 

\ SUITABLE changing-box to be used in conjunc- 
tion with this quarter-plate camera is described 
in the next chapter, and the film adapter is shown in 
Fig. 1. Before beginning to make the body of the 
camera the lens should be purchased. A single achro¬ 
matic lens of 5 in. or 5J focus is very suitable for a 
camera of this type. It is assumed that a single achro¬ 
matic lens of 5 J in. focus is to be used, and the dimen¬ 
sion given for the body will be approximately correct. 

It is better to make the body a little longer than 
required in the first place, then it may be cut down 



























































































































































































































































130 Something to Make 

afterwards, to suit any variation of the focal length 
of the lens to be used. Mahogany T 3 F in. thick is 
used, 7 in. long and 5J in. wide for the sides, and 
4J in. wide for the top and bottom. Square dovetails 
will probably be found the easiest method of jointing ; 
these may either be cut with a fretsaw or a chisel. 

A frame is glued in the back of the body, as shown 
in Fig. 3. Four strips of mahogany £ in. thick, 
two being 4| in. long by T 7 g in. wide, and two 3| in. 
long by f in. wide, are mitred together, or halved 
joints may be used if preferred. This frame is glued 
in flush with the back of the body, and strips of 
velvet are glued on the four sides, to ensure a light¬ 
proof fitting for the changing-box. 

Two angle brass strips, shaped as shown in Fig. 
4, are used to form the rebates at the back of the 
body for the accommodation of the changing-box. 
These are 5 in. long, bent at right angles along the 
length, one portion being J in. wide and the other 
\ in. wide. Holes for screws are drilled as shown, 
and screws J in. long should be used, so that they 
go through into the back frame and secure it. A 
small strip of brass 1 in. long by § in. wide, as 
shown in Fig. 5, is screwed to the underneath of 
the body, at the back, to prevent the changing-box 
being pushed too far through the rebates. 

The lens board consists of a single piece of ma¬ 
hogany 4| in. long by 3| in. wide and J in. thick. A 
hole is cut in the centre to fit the lens mount. The 
lens, as previously mentioned, is an achromatic 
meniscus of 5| in. focus, the diameter being 1 in. 
A plain brass tube, being 1 in. in diameter, and a 
circular piece of brass 1 in. in diameter with a central 









Fig. 2 



1 

o 

s. 

o 

o 

o 

v__ 

1 

• 

J 



Fig. 

4 



Fig. 5 



Fig. 6 



Fig. 7 





























































































































































































































































































































































































132 Something to Make 

opening of \ in. in diameter for the diaphragm are 
needed. The diaphragm is soldered in the end of 
the tube, and the flange is soldered on J in. away 
from the end of the tube. The flange is then fixed 
with screws to the back of the lens board, as shown 
in the sectional view of the body (Fig. 2), and the 
diaphragm will be flush with the front. 

The diaphragms for stopping down the lens are 
shown in Fig. 6. A strip of mahogany 2§ in. long 
by | in. wide and J in. thick is used for this, and three 
circular holes are cut as shown, the necessary dimen¬ 
sions being given. If preferred, brass in. thick 
may be used for making the diaphragms, the result 
being stronger and more durable. The values of 
the diaphragms are Fll, Fl6, and F22. Both edges 
of the diaphragm plate are bevelled as shown, and 
two strips of mahognay -J in. thick and 3| in. long 
and J in. wide, with one edge bevelled to fit the 
diaphragm plate, are glued to the lens board, so that 
the diaphragms may be moved across the lens, as 
shown by Fig. 7. Three notches are cut in the 
diaphragm plate at the top as shown, for a spring 
to catch in and hold the plate in exact position. A 
piece of watchspring, bent as shown in Fig. 6, is 
fixed in a recess cut in the top rail on the lens board 
(shown in Fig. 7), and the spring is fixed with a screw 
to the rail. A piece of mahogany lj in. long by 
If in. wide and J in. thick is glued to the lens board, 
above and below the diaphragm fittings, to form a 
seating for the shutter, as shown in Fig. 7. 

The shutter is of the drop-pattern, and will be 
found very effective in use. The working portion 
is shown in Fig. 9, and it is made from a single strip 











Mechanical Things to Make 133 

of mahogany 2f in. 
long by 1 in. wide 
and J in. thick. A T x ¥ 
in. rebate is cut along 
each side, and a cen¬ 
tral opening 1 in. long 
by § in. wide is cut, 
as shown. Two side 
rails, 4f in. long by 
J in. wide and J in. 
thick, with a T6 
rebate down one side 
of each, are glued to the front of the lens board, as 
shown in Fig. 10, for the shutter to slide in. Before 
the lefthand rail is glued in position, two small slots 
should be filed across it for the accommodation of the 
shutter catches, shown in Fig. 10. These are made 
from wire in. in diameter and If in. long. The 
top one is fitted in such a position that it holds the 
shutter at the top of the camera, covering the lens, 
and ready for an expo¬ 
sure. The bottom catch 
is used for making time 
exposures, being fixed in 
such a position that it 
arrests the shutter when 
the lens is fully un¬ 
covered. 

Rubber bands may be 
used for working the 
shutter; but a length of 
either brass or steel coiled 
spring, preferably the 





































































































































































































































































134 Something to Make 

latter, J in. in diameter (or less), is far better and 
more durable. A screw is fitted to the shutter, as 
shown in Fig. 10, and four screws to the lens board, 
so that two varying speeds of instantaneous expo¬ 
sure may be given. The ends of the spring are 
coiled in a loop and slipped over two of the screws 
on the lens board, and the coil is slipped over the 
screw in the shutter as shown. In making a time 
exposure, the spring is fixed to the two top screws, 
giving the slowest pull-down to the shutter and 
obviating any jar when the lens is uncovered. 

The lens board may now be fitted in the body of 
the camera, and its exact position is important. 
Place the changing-box in the rebates on the back 
of the camera, and fix a piece of ground glass at the 
front of the box to act as a focusing-screen. Two 
narrow strips of tin should be placed in front of the 
ground glass, along each side, to allow for the space 
occupied by the sheath. Then place the lens board 
in the body and move it backwards and forwards, 
ensuring that it is kept strictly at right angles to 
the body of the camera, both vertically and hori¬ 
zontally until the image of some well-defined object 
20 ft. away from the camera is in critical sharp 
focus on the ground glass. The lens board may 
now be fixed securely, by means of screws inserted 
through the body. It will be as well to glue strips 
of brown paper round the junction of the body and 
lens board—inside the camera—to ensure no light 
entering there. If thin glue is used, some of it will 
run in the joint and strengthen same. 

The front of the body may now be cut away, 
until there is just room left for the shutter to work 








Mechanical Things to Make 135 

freely. The brass strips for holding the changing- 
box should be unscrewed, and the body covered 
with thin black leather or cloth glued on. Cover 
the four sides, and have the join running along the 
bottom ; trim off the edges, and give the edges of 
the wood at the ends of the body a coat of dead-black. 

The front of the camera is shown by Fig. 11. This 
consists of three pieces of mahogany t 3 q in. thick 
clamped and glued together, to prevent warping. 
The centre piece is 3J in. long by 4| in. wide, and 
the two strips are 4j in. long by 1 in. wide. A hole 
lj in. in diameter is cut in the centre, and the front 
of the panel together with the edges are covered with 
leather similarly to the body, the back being coated 
with dead-black. The front is secured to the body 
by means of two small brass hinges at the bottom, 
and secured with two small brass catches at the top. 

Two view-finders should be fitted to the camera, 
and these may be purchased complete, ready for 
screwing in position. The ground glass should be 
placed in position in the changing-box, and the view¬ 
finders fitted so that they find the same view as that 
seen on the ground glass. A very sharp chisel must 
be used to cut the holes in the body and through the 
lens board, in fitting the finders, so as to avoid 
damaging the leather covering. A strip of wood 
with bevelled ends should be glued inside the body 
behind each finder, and brown paper strips glued 
over to ensure light-tightness. To complete the 
fittings of the finders, holes for the lenses are cut in 
the camera front. 

The interior of the camera body and changing- 
box should now be coated with dead-black. The 









136 Something to Make 

interior of the front, shutter and diaphragm fittings 
may either be coated with dead-black or french- 
polished. The exterior brass fittings should be coated 
with a dull black enamel, though they may be polished 
and lacquered, if preferred. 

Small holes should now be drilled through the 
body of the camera, for the accommodation of the 
two w r ire shutter catches, as shown in Fig. 1. These 
should be long enough (about If in.) to project 
T X e in. under the shutter, and to project sufficiently 
from the body to leave room for small knobs to be 
screwed or riveted on the ends. To prevent the wire 
catches being pulled out too far when making an 
exposure, short lengths of copper wire should be 
twisted round and soldered on the wire about £ in. 
inside the body. If desired, and they are a great 
advantage, spiral springs may be slipped over the 
catches, and fitted so that the top catch is kept pulled 
in with the tension and the bottom catch is forced 
out. This is an advantage, especially in the case of 
the bottom catch, as it ensures same not fouling the 
shutter when making an instantaneous exposure. 

To make an instantaneous exposure, the coiled 
spring is secured to the two top screws in the lens 
board, or, for a briefer exposure, to the bottom screws, 
giving more tension to the spring. When the top 
catch is pulled out by means of the knob, the shutter 
drops to the bottom and uncovers and again covers 
the lens. For a time exposure the lower knob is 
pressed and held, whilst the upper knob is pulled out 
as before. This arrests the shutter when the lens 
is uncovered, and the exposure is completed by 
releasing the lower knob. 







MAKING A CHANGING-BOX FOR 
HAND CAMERA 


PHE changing-box to be described, to accompany 
the camera dealt with in the previous chapter, 
carries twelve plates, and is of the automatic pattern, 
the sheath containing the plate being pushed into 
the bag, after exposure, when closing the shutter. 
Then the sheath only needs placing at the back of 
the changing-box, this method preventing two ex¬ 
posures on one plate. 

The body of the changing-box, shown by Fig. 1, 
consists of three pieces of mahogany in. thick 
dovetailed together. The two sides are 5J in. long 
by If in. wide, and the end 3| in. long by If in. wide. 
The front of the changing-box (see Fig. 2) consists 
of three strips of mahogany T 3 e in. thick, having a 
in. groove along the centre of one edge for the 
accommodation of the shutter. The two side strips 
are 5J in. long by f in. wide, and the bottom strip 
4f in. long by T 9 g in. wide. These three strips are 
joined by means of halved joints, as shown. 

To complete the front, a strip of mahogany 4f in. 
long by § in. wide and in. thick is let in flush at 
the back of the side rails, at the top, as shown in 
Fig. 2. The back of the rails is sawn down to the 
rebate, and the strip is glued in position. Along 
the front of the strip a piece of very thin velvet is 
glued, being let in slightly at the edges, to ensure a 
light-proof fitting for the shutter. 

The body of the changing-box is glued to the 

T 37 


138 Something to Make 

rails, and fixed with screws through the front, as 
shown in Fig. 3. If the box is to be french-polished, 
brass screws should be used, let in so far that the 
heads are just level with the surface of the wood, 
and the slots are all parallel with the grain of the 
wood. Then a rub over with a smooth file will 
level the screws, and ensure a neat appearance. 

The back of the changing-box is shown by Fig. 4. 
The door portion consists of three pieces of mahogany 
in. thick, clamped and glued together to prevent 
warping. The middle piece is 3 in. long by 3| in. 
wide, and the two outside strips 3| in. long by § in. 
wide. 

A strip of mahogany 3f in. long by f in. wide 
and in. thick is glued and screwed to the bottom 
of the body at the open end, the door being hinged 
to this by means of two small brass hinges, as shown 
in Fig. 3. Two small brass catches should be fixed 
at the top of the body, for securing the door when 

closed. 

To keep the 
plates in regis¬ 
ter, two stiff 
springs are 
used. These 
are made from 
a piece of old 
clock spring, 
and are 2 in. 
long by f in. 
wide, with a 
small hole 

Fig. 3.—Changing-Box Completed punched in one 


























Box 


!' 


f 




y/s 


4X 


V 


ii 


ill 




Jj 




*= 


Fig. 4.—Back of Changing- 
Box. 



h 




Fig. 9.—Shape of Brass Strip for 
Changing Plates 



Fig. 5.— 
Springs for 
Changing-Box 



Fig. 10.—Brass Sides 



I 39 






























































































































































































































































































140 Something to Make 

end and shaped as shown in Fig. 5. Recesses for 
the accommodation of these are cut inside of the 
door, as shown by the dotted lines in Fig. 4. Then 
the springs are secured with screws in the recesses, 
so that the bent portions press on the back of the 
sheaths and keep the plates in register. 

The bag is made either from very thin leather 
or light-proof cloth, to the shape shown by Fig. 6, 
and is glued to the open end of the body. Where 
the body is glued to the front rails, a saw-cut should 
be made along the bottom rail, to a depth of a J in., 
sawing about in. of the rail away, and leaving a 
rebate for gluing in the bag, so as to ensure the 
sheaths clearing when being pushed in the bag. 
Strips of brass may be screwed over the glued edges 
of the bag, if desired, along the two sides and back 
of the body. 

The shutter shown by Fig. 7 is made from 
mahogany J in. thick. It is made in three pieces 
clamped and glued together, one piece 2| in. long 
by 5 in. wide, and two strips 5 in. long by | in. wide. 
Along the top a strip of mahogany 3| in. long bv 
f in. wide and in. thick is glued both to the back 
and front, and shaped to form a finger-grip as shown. 

A iV* 11 * rebate is then cut along each side and 
the bottom edges, to fit the grooves in the front 
rails. The shutter is next cut straight across, with 
a very fine saw, and a hinge of very fine leather, 
3j in. long by £ in. wide, is glued flush in the groove 
cut at the back of the shutter, as shown in Fig. 8. 

The arrangement for changing the plates is shown 
by Figs. 8 and 9. This is merely a strip of brass 
3| in. long by J in. square. It is shaped as shown 






Mechanical Things to Make 141 

in Fig. 9, to clear the rebates on 
the front rails, and is screwed to 
the back of the shutter, in. 
from the bottom, as shown in 
Fig. 8. Ordinary small wood- 
screws may be used, securing 
through holes drilled in the brass 
strip, as shown ; or a stronger 
method is to drill and tap the 
holes in the brass, and fix with 
metal-screws through the shutter. 

When the shutter is pulled Fl |; °I 

out this brass strip slides in front Box 
of the first sheath, but rises above it and allows the 
plate to come into register. On pushing the shutter 
back again, the brass strip catches the top edge of the 
sheath, and so pushes it into the bag. 

The sheaths may either be made or purchased. 
To make them thin tin-plate is required, and a piece 
of metal slightly wider and thicker than a quarter- 
plate, to form a template. The metal is cut to the 
size and shape shown by Fig. 9a, and the three 
edges are bent, where shown by the dotted lines, 
over the template, forming grooves for the accom¬ 
modation of the plate. The sheets of tin-plate 
should be cut to shape and emery-papered until a 
smooth matt surface is obtained, and are then held 
over a clear fire until a very dark blue colour is 
reached before bending into shape. This saves 
coating with dead-black, which chips and ^causes 
holes in the negatives. 

The inside of the changing-box has a brass lining 
on each side. This is cut from a piece of brass fa in. 












































































































142 Something to Make 


thick and 4^§ in. long by If in. wide. Three of the 
corners are cut away, as shown in Fig. 10, and then 
J-in. projecting portions at each end are bent at right 
angles, along the lines shown dotted in the illustra¬ 
tions. The bent portions should be bent in opposite 
directions on the two plates, and holes for screws 
should be drilled as shown. These brass strips are 
screwed to the sides of the body, as shown in Fig. 1, 
p. 129, leaving a clearance of J in. in front and J in. at 
the back, to enable plates to be changed properly. 

The finished changing-box (the bag is left off 
for clearness) is shown by Fig. 3. The box may 
either be french-polished or coated with dead-black ; 
or the body portion may be covered with leather to 
match the camera, and the front rails and shutter 
french-polished. 



Fig. 8.—Back View of Shutter 
for Changing-Box 



Fig. 9a.—Shape of Tin-plate 
for Sheath 



























































































MAKING A CINEMATOGRAPH CAMERA 


A LTHOUGH an ambitious undertaking, it is quite 
possible to make a small motion picture 
camera, provided great care is taken in keeping to 
measurements and in fitting the mechanism. The 
apparatus to be described is capable of filming a 
suitable well-lit outdoor subject of short length, 
though, of course, there are certain inevitable limita¬ 
tions as compared with an expensive and elaborate 
professional cinema camera. 

The external dimensions are 7 in. long, 4| in. 
wide, and 6| in. high. Fig. 1 shows the film side, 
the lid being removed. A roll of unexposed film 
about 25 ft. long is contained on the wooden spool a. 
It passes out over a guide roller b, and is carried 
through the gate c, in which is the exposure opening. 
Emerging from the gate it is carried round the 
intermittent sprocket wheel d, being prevented 
from slipping by a spring cradle e, furnished with 
two rollers. Lastly, it travels to the take-up spool 
f. The exposure is given by the rotary shutter g, 
caused to revolve by the bevel wheels ii and i. At 
j is the lens. Probably the experimenter may only 
be able to afford a rectilinear, perhaps taken from 
a small folding camera. It should be of about 
3-in. focus, and capable of covering a picture at least 
1 in. by § in. 

It would not do merely to run the film continu¬ 
ously through. This would only produce a blurred 
image. It has to be stopped at regular intervals 

I 43 


T44 Something to Make 



for the exposures, and then moved rapidly on to 
the extent of one picture space, or four perfora¬ 
tions, which is done by the intermittent escapement. 

In the present case this consists of a three- 
slotted “ Manx ” wheel, cut in in. thick sheet 
brass. To set it out, draw an equilateral triangle 
with 1-in. sides. Bisect each side, and draw lines 
a, b and c (Fig. 2) through each bisection from the 
opposite angle. Measure off J in. along the lines 
a, b and c, and on these points as centres describe 
circles 1 in. in diameter. Also, with the middle of 
the triangle as centre, describe a fourth circle 1 in. 
in diameter. This gives the outline of the Manx 
wheel, and it only remains to mark three slots d, 
e and F, | in. wide by § in. long, along the lines 
a, b and c. A small boss f in. thick with a J-in. 
diameter hole for the spindle may be soldered on, 
or the whole may be turned in one piece. 

The Manx wheel is caused to move and stop 
intermittently by means of a pin-wheel, shown in 
plan and elevation by Figs. 3 and 4. It may either 
be made from two y^-in. pieces of metal soldered 
together, or turned solid in J-in. material. The 






























Mechanical Things to Make 145 

lower disc is lj in. in diameter, and the upper one 
1 in. in diameter, having a curved portion cut away. 
A metal pin ^ in. thick is soldered or screwed in 
at a. A boss bored for a spindle has to be provided. 

The Manx wheel is fitted so that one of its curved 
sides bears lightly against the central disc, as shown 
in Fig. 5. At every revolution of the pin-wheel the 
pin enters one of the slots and turns the Manx wheel 
one-third round, the next curved side being then 
locked against the central disc till the pin again 
comes round. As the three-picture sprocket wheel 
is on the same spindle as the Manx wheel, this is 
moved round to the extent of one picture for each 
rotation of the pin, with intervals of stoppage 
between. 

The three-picture sprocket wheel will have to 
be turned in a lathe, and the triangular projections 
or teeth (there are only twelve each side) obtained 
by patient filing. Since each picture space is J in., 
three spaces will equal in., which will be the cir¬ 
cumference of the sprocket wheel without the teeth. 
Therefore the diameter will be a trifle over ^ in., 
or more exactly 0*716 in. It should be tested by 
trying on it a piece of positive film containing three 
pictures and twelve holes. Exclusive of the boss, 



J 






















































146 Something* to Make 

the sprocket is If in. long. Fig. 6 is a front, and 
Fig. 7 an end elevation. 

The driving mechanism may now be explained. 
Fig. 8 shows the opposite compartment of the camera, 
the side and handle being removed. The partition 
on which the wheels are mounted is of wood § in. 
thick, having two metal plates each T \r in. thick 
screwed on to it at opposite sides and bored to act 
as bearings. The driving wheel A is 4 in. in diameter, 
and gears with a f-in. diameter wheel b, on the same 
spindle as the pin-wheel c. A second f-in. diameter 
wheel d, also gearing with the driving wheel, is on 
the same spindle as one of the small bevel wheels in 
the other compartment, and therefore drives the 
shutter round once for every revolution of the pin- 
wheel. On the spindle of the driving wheel is also 
a 1-in. diameter pulley wheel e, connected by a rubber 
band to a second pulley wheel f on the same spindle 
as the take-up spool. This, therefore, rewinds the 
exposed film. The rubber band needs to be of such 
a strength, and so adjusted, as to slip on the lower 
pulley when the handle is turning faster than the 
rate of rewinding, which will happen as the roll of 
exposed film increases in size. 

Fig. 9 is an end view of the mechanism, the 
front of the camera being removed. The lettering 
is identical with Fig. 8. In addition, the handle 
g is seen, and the rotary shutter 11 , which consists of 
a thin blackened metal disc, having an aperture of 
half a circle. The round opening 1 is in the panel 
behind the shutter, in line with the lens. 

Fig. 10 shows the various panels and compart¬ 
ments from above, the top and both sides being re- 









Mechanical Things to Make 147 


moved. When compared with the other diagrams, 
all practically drawn to scale, it is self-explanatory. 

The spring cradle for the jg-in. diameter pressure 
rollers is shown in front and end view by Figs. 11 
and 12. It will be seen in Fig. 1 how it is mounted 
in a small bracket, with a coiled spring on the handle 
to keep it pressed against the sprocket. To prevent 
it twisting, the handle part should be of square 
section, and there should be a square hole in the 
bracket. 



Fig. 12 


► 

• 

- - t 'f* 

* 

- - 4 

iff. 

/ 


v — ~ % 
i 5 


yrrm 

i ' 

o 


* T 
-O , 

>’ ' < 

A> 


O 

i. 


L - • - 4 

j 

sU 


Fig. 13 


Fig. 14 


* - 


- / - 

- -» 

i; 

i 

TT 

) 

’fW* 

PI 

111 

0 



o 

Si 

!, 

* 


"h 

•A 


Fig. 15 


Fig. 16 


• t 



% l 
• f 


Fig. 17 


Fig. 18 


The gate may be of hard wood, well smoothed. 
Fig. 13 shows the front half, Fig. 14 being a section 
indicating how the channel is recessed for the film. 
The back half (Fig. 15) fits inter the front, as will be 
noted from its section (Fig. 16). In both, small 
well-polished and rounded strips l in. wide are glued 
on at top and bottom level with the central recess, 
as indicated by the dotted lines. Thin, round, 
screw-threaded metal rods are inserted at either side 
of the front half, and slightly larger holes are bored 
in the back half so that it moves freely on them. 
Coiled springs are then slipped over the rods, a 
milled-head nut being placed behind each to adjust 
the tension, as seen in Fig. 1. It must be only just 




































148 Something to Make 

sufficient to stop the film over-running after each 
intermittent movement of the sprocket. As will be 
seen in Figs. 1 and 10, the gate is boxed in, so that 
no stray light reaches other parts of the camera. 

The guide roller is shown in front and end view 
by Figs. 17 and 18 ; it simply runs free on its 
spindle. 

The spools are lj in. in diameter, and of the 
shape shown by the dotted lines at a, in Fig. 10. 
The top spool runs free and the film is not secured 
on it, but the bottom one should be fixed to the 
spindle by a pin through the boss as at b, and should 
also have a short piece of curved spring c screwed on 
it, to grip the end of the film. 

The camera door on the film side should be cov¬ 
ered on the inside with black velvet, and is secured by 
spring clips at the bottom and brass hooks and pins 
at the top. The opposite side of the camera should 
be fixed with round-headed screws, so as to be re¬ 
movable if required for adjusting the mechanism. 
The whole interior of the camera should be blackened. 

A small finder may be fitted outside, or there 
is room for recessing one into the front, above the 
shutter. 

The handle should be turned three times per 
second, which is equivalent to sixteen pictures. 
Since the shutter opening is one-half, the exposure 
is ^ sec., and only subjects which can be taken 
with that duration of exposure should be attempted, 
the lens stop being chosen to suit the light. If a more 
expensive lens with a larger aperture is fitted, the 
shutter opening should be made one-third of a circle, 
instead of one-half. 








MAKING A HOME CINEMATOGRAPH 


T HE cinematograph to be described is of com¬ 
paratively simple construction, and is intended 
to be used with an ordinary full-size magic lantern to 
supply the light. By “ full-size ” is meant one 
having a 4-in. diameter condenser whose centre is 
at least 5J in. above the base. The front lens or 
“ objective ” has to be unscrewed from the lantern, 
the latter being then stood a sufficient distance 
behind the cinematograph to throw a narrow beam 
of light only just large enough to cover the picture 
opening at the back of the gate. Since the gate 
and some other parts of the projector are of wood, 
the machine must not be used with any source of 
light producing great heat, such as the arc lamp 
or limelight. With an oil lamp at a safe distance, 
incandescent gas, or preferably an electric bulb of 
50 watts or more, connected by a flexible wire and 
adapter to a household fitting, there will be no 
danger. Of course, if the usual inflammable celluloid 
films are shown, there must be no heat on the film, 
no fire near, and no smoking allowed; while the 
slide carrier should be inserted in the lantern with 
a square piece of metal in one side, so that the light 
can be promptly cut off if there is a stoppage or 
hitch. 

Fig. 1 is a view of the machine from the film 
side. The framework or support a is in. high 
and 6j in. long. The upright is J in. thick and has 
a metal plate ^ in. thick screwed at each side, and 

149 


i5o 


Something to Make 



( v> 

^ a. 




n 

• 


0 J K 


3 

®§f 


'it 


> 

7f 

n, 



Fig. 1 


bored identically to receive the 
various spindles. The base, to 
which the upright is screwed, is 
in. long, 4| in. wide, and 
| in. thick. 

The film b is carried 
from the upper spool c 
into the hinged pressure 
gate d, which contains 
the mask or opening for 
the picture. On emerg¬ 
ing, it passes over an 
intermittent sprocket 
wheel e, being prevented 
from slipping by a 
curved spring f. Lastly 
it is wound off on the 
lower or “ take-up ” spool G. The projecting lens by 
which the enlarged image is thrown on the screen 
is at h, while i is a two-bladed shutter caused to 
revolve by the bevel-wheels j and k. The driving 
handle is shown at l. 

Fig. 2 illustrates the mechanism side of the 
projector, and it will be seen that this is almost 
the same as that of the cinema camera, though 
differently arranged. The 4-in. diameter spur wheel 
a, turned by the driving handle, gears with a f-in. 
diameter wheel b on the same spindle as the pin- 
wheel c. This pin-wheel moves a three-slotted 
“ Manx ” wheel one-third round at every revolution, 
and that, in turn, causes the three-picture sprocket 
wheel on the opposite side to move to the extent of 
one picture space. Since § divides 5J times into 


























Mechanical Things to Make 151 


4, 5J pictures will be shown to every turn of the 
driving handle. Therefore, three turns per second 
will be necessary to obtain the ordinary projecting 
speed, that is, sixteen pictures per second. 

The 4-in. wheel also gears with another f-in. 
wheel d, on the same spindle as one of the bevel 
wheels that drives the shutter. In addition, a 
1-in. diameter pulley wheel e is fixed on the spindle 
of the 4-in. wheel, a similar pulley wheel f being 
fixed on the spindle of the lower spool. A rubber 
band is passed over these pulleys, the tension being 
carefully adjusted so as to let the lower pulley slip 
as film accumulates on the spool. Note that the 
band is crossed. * I 

Fig. 3 gives an end view of the mechanism with 
the same lettering as Fig. 2. At g will be seen the 
spring which presses against the film on the sprocket 
wheel. 

The Manx wheel, pin-wheel, and 
sprocket wheel are identical with 
those in the cinema camera, so that 
there is no need to repeat 
the directions for making 
them. The gate, however, 
differs considerably. Fig. 4 
is an elevation of the fixed 
half, which is screwed to the 
upright, while Fig. 5 is 
a section. Hard wood 
should be used, the 
channels being accurately 
cut and well smoothed. 

Figs. 6 and 7 give re- Fig. 2 



























152 


Something to Make 


spectively a front view and a section of the movable 
half. On the inner side are screwed two flexible 
steel springs A and b, to press gently on the 
margins of the film. The manner of bending the 
springs is shown by the end section (Fig. 8). It 
will be noted from Fig. 7 that the opening, which 
measures 1 in. by £ in. inside, is bevelled outwards 


towards the back, 
and w e 1 1 - 
£ in. wide are 
bottom of the 
come level with 
dicated by the 
back half of the 
to the front by 
hinges, and a 
fitted for fasten- E yfjj 
being cut in the 
Fig. 9 gives 
si ons for the F ^ 
spring, Fig. 
it should be 

screwed behind Fi £- 3 

The shutter (Fig. 11) is a 4-in. diameter disc of 
thin blackened metal, having two openings A and b 
cut in it at an angle of 97°. It should have a hole 
in the middle with a small boss and set screw, so 
that the distance from the lens may be altered if 
necessary. It must be adjusted so that one of 
the opaque sectors comes before the lens while the 
film is shifting from one picture to another. 

The objective should be of 3-in. focus, otherwise 
the distance from the film of the panel that holds 



Thin, rounded 
smoothed strips 
2 glued at top and 

fixed half, to 
the recess, as in- 
dotted lines. The 
gate is attached 
two small brass 
spring clip is 
ing, a little recess 
front to engage it. 
the dimen- 
s procket 
10 showing how 
curved. It is 
the gate. 














































Mechanical Things to Make 153 


ynm? - 

o 

■III, 


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ITT 

1 

7 

i 

i 

r 


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r 

o 


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'•Mill. 


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Fig. 4 

► - - 

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Fig. 6 






Fig. 5 Fig. 7 


it will have to be altered, and that would involve 
other changes. A proper small-size cinema objective 
in a rack-and-pinion focusing jacket would be 
best. Those, however, who wish for something 
inexpensive will find that even a single biconvex 
magnifying glass of 3-in. focus and 1-in. diameter, 
mounted in a sliding tube, will give a fairly decent 
image ; while a somewhat better result is obtained 
by mounting two plano-convex lenses, one of 8-in. 
focus, and the other of 4-in. focus, in a tube, lj in. 
apart, with their curved sides facing towards the 
screen. 

The spools are of wood, 1 in. in diameter, and 
lj in. long, with projecting bosses J in. long, and 
\ in. in diameter. Thin metal discs 3 in. in diameter 
are screwed at either side, and a short piece of spring 
is screwed in the middle. The spring is only used 
to secure the film on the bottom spool. The latter 
is fixed temporarily to its spindle by a pin through 
the boss, but the top spool must run free on a motion¬ 
less spindle that is glued into the upright. To 



























154 Something to Make 

facilitate changing, it is advisable to have at least 
three spools. 

The machine may be further simplified, if desired, 
by omitting the shutter, at the expense of a little 
“ raininess ” in the picture. If this is done, the 
f-in. wheel d and the two bevel wheels are not 
needed. The lower spool could also be dispensed 
with, and the film allowed to run over the edge 
of a table into a basket or box placed below, in which 
case the two pulley wheels may be discarded. 



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I 

jtL. 


Fiji. 9 


Fig. 10 















MAKING A MAGNETIC COMPASS 


T HE magnetic compass shown complete in Fig. 1 
costs scarcely anything, and is very useful to the 
scout or tourist. 

The materials needed are : A piece of |-in. fretwood 
about 6 in. by 5 in. for the box, a piece of glass 2| in. 
square, a thin white card, some gummed binding tape, 
a few brass paper-fasteners (Fig. 2) f in. long 
altogether, the mainspring from an old watch, and a 
little fine iron wire. A small horseshoe magnet is also 
required. 

The box is 2b in. square and f in. deep outside. 
Therefore the bottom will be 2j in. square, the sides 
2\ in. by J in., and the ends 2 in. by \ in. Smooth all 
the parts with glasspaper, and fix together with very 
small french nails. 

Take a larger nail, about J in. long, and file it down 
at the point till only ^ in. long. Round the point 
with a fine fde until conical and smooth, instead of 
looking as if it had been trimmed like a blacklead 
pencil. Then, with an awl, start a hole in the bottom 
from outside the box, exactly in the middle, and drive 
the nail in, keeping it perfectly upright as at A in 
Fig. 3. This will be the pivot for the needle. 

The holder for the needle is a paper-fastener, 
having a little boss made in the head to revolve on 
the pivot, as at b in Fig. 3. To do this, take a nail 
about lb in. long and file the point to a blunt rounded 
shape, as seen at a in Fig. 4, and also enlarged at b. 
Bend the prongs of the fastener slightly apart, rest it 

i55 


156 Something to Make' 

upside down on a piece of wood, hold the nail exactly 
in the middle of the head, as in Fig. 5, and give it a 
smart tap with a hammer, but not too heavily or the 
nail will go through. If the blow is just right, a round 
boss will be indented in the head. 

Next, gently bend out the prongs of the fastener, 
as in Fig. 6, getting both sides even, and bend down 
about in. at each end. Then try it on the pivot 
in the box, when it should balance and turn nicely. 

The “ needle ” is in two parts, each in. long. 
Straighten the end of the mainspring and nick it 
across with the file J in. from the end, where there is 
usually a hole, snapping off and throwing that portion 
away. Mark two pieces -ff in. long, and file nicks 
so that they readily break off. To magnetize them, 
make a diagonal nick at one end, as at a in Fig. 7, 
notice which side of the magnet has a mark on it (this 
is the north pole), and lay the piece of spring across 
the two poles as shown, taking care the marked end 
of the spring rests on the unmarked, or south side of 
the magnet. 

Then with the finger, pressing slightly, push the 
piece gently to and fro along the magnet for a distance 
of about one inch, as indicated by the dotted lines. 
Repeat this to and fro movement about twenty times 

without lifting the piece ; 
then reverse the latter, 
still keeping the marked 
end on the unmarked pole, 
and go through the move¬ 
ment another twenty 
times. Lastly, do the two 
edges in the same way. 



Fig. l 



















Mechanical Things to Make 157 



Remove the piece and see if it will easily lift up a 
needle or steel pen. If so, as will probably be the 
case, it is sufficiently magnetized, but if it only lifts 
feebly, proceed again as before. Do both pieces in 
this way, keeping them separate till ready. 

'Now, with four thin wire loops, as at a, b, c, d, in 
Fig. 8, bind the pieces of spring at each side of the 
fastener, one with its north pole, or marked end, out¬ 
wards, and the other with its south pole outwards. 

The card is next prepared, as in Fig. 9. This is 
lj in. in diameter, the intermediate circle being 1 in. 
in diameter and the innermost one J in. Divide it into 
eight equal parts by lines from the centre, when the 
method of lettering and forming the star will be clearly 
evident. Fill it in neatly with Indian ink. Cut out a 
small piece at A and b for the ends of the fastener to 
clip under, and also cut out the inner circle. Fig. 10 
shows how to attach the card to the needle. The 
intricate part of your work is now completed. 

Try the finished needle and card on the pivot, as in 
Fig. 1, and note that it balances well. If not, stick 



































158 Something to Make 

a small piece of paper under the higher side, or shift 
one of the wire loops. 

It is quite natural for the magnet to “ dip,” and 
this has to be corrected. See that the needle turns 
readily and always comes to rest in the same direction, 
with its north pole pointing northwards. 

Clean the glass, lay it on the box, and make sure 
that the central boss, while just far enough away to 
turn freely, is sufficiently close to prevent the needle 
“ unshipping ” should the box be turned over. If 
not, the pivot ought to be a little longer. All being 
found correct, bind the glass in place with four strips 
of narrow gummed tape, or even by using glue or 
pasting round strips of stout paper. 

If the worker has any luminous paint, he might 
like to coat the card with it before marking and 
lettering. Then the compass could be used in the 
dark. 





HOW TO MAKE AN AUTOMATIC 

MACHINE 


r IMIE automatic machine shown complete in Fig. 1 
will deliver a box of safety matches on insert¬ 
ing a penny, or may be adapted to supply sweets, 
chocolate, etc. It will not take smaller coins, neither 
will it calmly appropriate the penny when empty. In 
the present instance the match-boxes are supposed to 
be the usual size sold in packets of a dozen, that is> 
about in. by 1| in. by § in. Though the drawings 
might convey a contrary impression, the machine is 
really very simple in construction, requiring nothing 
but accurate measuring and cutting. It is made 
entirely of fretwood J in. and in. thick. 

First set out and cut the plunger (Fig. 2) in J-in. 
wood, and midway, at a and b, insert two small 
screws to project about J in. 

Next prepare the handle-piece, shown in plan and 
section by Fig. 3. This is also of J-in. wood, but the 
shaded portion A is repeated in 
J-in. wood and glued under¬ 
neath, as indicated in the sec¬ 
tion, so that the thickness at 
this part is J in. 

Now cut the piece a seen 
at the top in Fig. 4, 8 j in. by 
4J in. by J in. Draw a line 
lengthways across the middle, 
and, along this line, measure 
off lj in. from the end. With 

J 59 



Fig. 1 












Something to Make 


j6o 


M-4'/2* - - >\ 



mv, - 

T 

► • 2"- ^ 

'vii/jft _* 


* 

CD 

t 


s: 

• 


i 

• 

_ 

.k 


7 ^=— 1 

Fig. 3 



this point as centre, describe a circle b ljg- in. in 
diameter. Measure off a second distance 3J in. from 
the end, and at that point describe a circle If in. in 
diameter. Cut the two circles out with a fretsaw. 

The magazine comes next, Fig. 5 being a front 
and Fig. 6 a back view. The sides are J in. thick and 
the ends \ in. At the bottom of the front is cut a 
slot a (Fig. 5) J in. deep. The back is in two pieces. 
One piece b (Fig. 6) is f in. wide and is raised | in. 
from the bottom, while above this (not shown) is a 
piece 4J in. by 3| in., fixed with small screws, so 
that it can be removed at will for loading up. The 
top (seen in Fig. 1) is 3J in. by 2 in. 

Fig. 7 explains the arrangement of the mechanism. 
The handle-piece a is laid over the plunger b on the 
board having the two circular holes. At c and d are 
glued J-in. strips to act as guides for the plunger, while 
at e the magazine is fixed by screws from under¬ 
neath, with its narrow slot towards the plunger. A 
strip f, J in. wide and thick, is glued at the opposite 
end as a stop. When the handle is pulled out, as 
shown, a square recess is formed over the smaller hole, 
in which the penny is laid flat. Any coin smaller than 
a penny will slip through and be returned, but the 
penny cannot do so. On pushing the handle forward, 
the penny is pushed against the plunger b, which is in 

































Mechanical Things to Make 161 

turn pushed through the slot in the magazine and 
forces out the lowermost match-box through the 
opening at the back, whence it slides down an inclined 
chute to the purchaser. Meanwhile, the penny has 
reached the larger hole and falls through into a 
receptacle, another box simultaneously coming into 
position ready for the next coin. The plunger will 
not work without the penny, and is protected in the 
finished machine by a cover. 

Cut a block of wood the same size as a match-box, 
but 1J in. thick. This is placed on top of the pile in the 
magazine, so that, when the matches are all delivered, 
the block (being too thick to pass through the opening) 
will stop the plunger working, and prevent the loss of 
the penny. 

We may now proceed with the base (Fig. 4), which 
consists of a back and two sides, into which latter the 
top is recessed to lie flush. The chute d is fixed by 
nails through the sides. At the front end of the chute 
glue a strip \ in. wide and thick, as seen in Fig. 1. 

The cover (Fig. 8) has a piece just over f in. deep 
removed at the front, and an opening in the top to 
pass over the magazine. It is glued on, after the 
mechanism has been well tested. 



Fig. 5 


K 


Fig. 6 


Fig. 8 


























































162 


Something to Make 


The money receptacle (Fig. 9) has a small hole 
bored near the top at opposite corners, as shown, and is 
fixed by screws through the sides exactly below the 
opening c (Fig. 4), so that it will swing downwards by 
its own weight. The side nearest the pivoting 
screws should be rounded at the top with file and 
glasspaper, so that there is no obstruction to swinging. 
A third screw inserted through the bottom corner 
keeps the box normally in position. 

Lastly, cut a piece 4 in. by 2^ in. by \ in., and 
nail it in at the front, as seen in Fig. 1. The whole 
may, if desired, be painted or varnished outside. 

To load up, unscrew the back of the magazine and 
insert the boxes one by one, with the wooden block on 
top. The magazine holds six boxes, but, of course, 
it might be made longer if wished. Then screw on the 
back again. To obtain the money, take out the single 
screw in the side, so that the money receptacle swings 
down. 








AUTOMATIC MACHINE FOR 
VIEWING POSTCARDS 


PHE cabinet shown complete in Fig. 1 will hold a 
band of a dozen picture postcards, bringing 
them one by one before a magnifying eyepiece on 
turning the handle at the right. The band can be 
changed for another in a few seconds. 

The case consists of two sides, back, front, bottom 
and a sloping top in two pieces, the material being 
J-in. thick wood, except where otherwise stated. The 
two sides, one of which is to serve as a door, are | in. 
thick, and are set out as in Fig. 2, to the dimensions 
indicated. The back is 2 ft. 2 in. long, and the front 
1 ft. 11^- in. long, both being 8 in. wide. The 
bottom looks better if it projects about J in. all round, 
and may therefore measure in. by 7J in. 

The flat part of the top is 8 in. by 4j in., while 
the sloping part is 8 in. by 4J in. The front and the 
two top pieces require bevelling at the edges where 
they meet, as seen in Fig. 1, and in the section, Fig. 3. 
This may be done with penknife and glasspaper. 
See that all the pieces fit well, but do not yet fix them 
together. 

The bracket to support the changing arrange¬ 
ment is in three pieces, as shown in Fig. 4, A and b 
being J in. thick, and c 1 in. thick. Screw c on b, but 
do not fix a till the other parts are ready. A hole J in. 
in diameter is bored \ in. from the top of a and b, 
taking care both holes are in line. 

The changer (Fig. 5) is of |-in. wood, the edges 

163 


164 Something to Make 

being well rounded with glasspaper. Obtain a short 
piece of round wooden rod just under f in. in diameter, 
so that it will revolve easily, but not loosely, in the 
bracket holes. Cut a piece If in. long (a, Fig. 6), and 
at one end cut a slot J in. wide by J in. deep, to fit 
on the right-hand projection of the changer. Glue 
this tightly on. Cut a second piece (b, Fig. 6), f in. 
long, and split it in three by two cuts J in. apart. 
Take the two outer pieces, and glue them at either side 
of the left-hand projection. When quite set, trim both 
projections carefully with knife and glasspaper till 
they are quite round. A small turned handle with a 
metal screw (c, Fig. 6) will also be required. 

Now take the right-hand side of the case and bore 
a hole f in. in diameter, first marking its centre 2f in. 
from the back and 4f in. from the top, as seen at 
A in Fig. 2. 

In the flat part of the top cut an opening 6 in. by 
2f in., and in the back, \ in. from the top, cut 
another opening 6 in. by 2j in. These, seen at a 
and b in the section (Fig. 3), are to admit light 

for viewing the postcards. They 
may be left open if desired, but 
it certainly looks better if pieces 
of thin ground glass are fixed 
behind them, which can be done 
by screwing little metal strips 
across the corners inside. 

I 11 the sloping part of the top 
cut a circular hole 2 in. in di¬ 
ameter, its centre being If in. 
from the bottom edge. This is 
to receive the lens, a bi-convex 



Fig. 1 
























Mechanical Things to Make 165 





* 


1 - € '/4‘-> 



1 A 


Fig. 3 



Fig. 4 


L 


Fig. 2 

|f- - - - 65/* --**| 



6 


Fig. 6 


Fig. 5 

one of 4 J - i n. 
optician will sup- 
shillings. Glue a 
the hole to support 
brush a little glue 
and lay the lens 
which is shown 



t==zj 


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IL-CLZZ) 


Fig. 8 

focus, which an 
ply for about two 
bent wire ring in 
the lens, then 
round the hole 
in the position 
at c in Fig. 3. 
now be put to- 
First nail the front 


The parts may 

gether with small french nails, 
and back on the fixed side. Then nail on the bottom, 
holding the left side temporarily in place while doing 
so. Next fix in the bracket by screws through the 
piece b, taking care the hole is exactly over that in 
the side. Insert the longer projection of the changer 
through the holes in the bracket and side, then fit the 
second projection through the other piece a of the 
bracket, and screw this on to the piece c, as shown 
by the dotted lines in Fig. 4, making sure the two holes 























































166 Something to Make 

are level. Screw the handle on at the right, from 
the outside. The two parts of the top are then 
cautiously fixed with glue and one or two nails, 
being careful not to split the wood near the openings. 
Lastly, the door is fitted by means of a nail through 
the top and bottom, to act as pivots, as seen in 
Fig. 7, a small wooden block glued just inside at 
the bottom, for a stop, and a screw knob provided. 

The postcards are secured together by gluing 
pieces of tape If in. long at the back as in Fig. 8, 
leaving J in. space between each card. When the 
dozen is completed, the ends are joined in the same 
way. The band is easily slipped over the bracket on 
to the changer, as in Fig. 7, and on turning the handle 
slowly one card is changed for another in a prompt 
and certain way that will puzzle anyone who does 
not know how it is done. The bands fold up to the 
size of a postcard when not in use, and occupy scarcely 
any space ; in fact, a dozen bands (144 cards) may be 
kept in quite a small box. 







HOW TO MAKE A GRAMOPHONE 
AND TO USE IT 


'T'HE title of this chapter requires some qualifica- 
tion at the outset. Actually to make a 
gramophone from raw material, detail for detail 
from A to Z would demand the expert skill and 
workshop facilities of half a dozen separate trades. 
It is rather with the correct make-up and practical 
after-maintenance of a reliable instrument built up 
from finished and semi-finished parts, that we are 
here concerned. 

The enterprise, however, is well worth while, 
for, apart from the satisfaction of making and the 
manual training such work must needs impart, it 
is possible to produce a first-class machine at home 
at less than one-half the cost of a ready-made one 
of inferior quality. (And who can deny that an 
inferior gramophone is an abomination !) 

It will be assumed in the first place that those 
who propose to follow these practical instructions 
aim at the production of a machine which really 
plays well ; rendering the record engraved on 
every disc revolved upon it to the best advan¬ 
tage ; which, after all, is the gramophone’s raison 
d'etre ! 

Lest this remark should appear superfluous, it 
must be frankly stated that too many of the latest 
patterns of the talking-machine do not and cannot 
do justice to good records. Among them are certain 
freak forms, much degenerated from the earlier in¬ 
strument. Freaks are those of excessively light 

167 


168 Something to Make 

construction, of minimum dimensions, of advertised 
“ portability.” Now, de facto, machines of this 
character are self-condemned as musical instruments 
because substance, solidity, even sheer weight pro¬ 
perly disposed, are actual qualities of merit in any 
gramophone. It is the same with the pianoforte ; 
a lightly framed, flimsily encased piano must always 
yield a thin, shallow and “ trashy ” tone. The 
physical reason for this is not far to seek ; one is 
dealing with a sound-centre; a propagating source 
whence sound is projected or radiated ; the sound¬ 
wave must have something solid to “ kick off ” 
from, as it were. 

There is another point in the modern gramo¬ 
phone’s disfavour ; its suppression of the external 
horn. Even in the case of large and expensive 
cabinet gramophones the so-called “ internal horn ” 
occupies a space much too constricted to permit of 
the best and fullest development of tone. It is not 
only a question of sound-volume, but of the quality 
of the sound reproduced by a properly proportioned 
external horn. Moreover, even assuming that 
adequate dimensions could be given to an amplifier 
stowed within the casing of a self-contained machine 
(which in practice cannot be done) there remains 
one objection which might be overlooked, namely 
that this internal horn is necessarily a material 
portion of the whole casing and therefore subject 
to every vibration affecting the latter. The very 
best spring-motor obtainable does not revolve with¬ 
out a certain amount of sound—the sound of matter 
in motion. Such sound may be and is, in fact, 
slight enough in itself; but when amplified, first 





Mechanical Things to Make 169 

by the general resonance of the whole fabric of the 
casing and afterwards by the conical expansion of 
the internal amplifier itself, it becomes developed 
into a considerable volume. Added to this is the 
harsh sound caused by the friction of the reproducing 
needle in the groove of the record—a small noise 
enough, but one of tearing and scraping ; this vibra¬ 
tion, too, becomes amplified, not only by the horn 
expansion, per se , but also through the resonant 
body of the cabinet enclosing the internal horn. 
In brief, the so-called “ hornless ” gramophone must 
always reproduce the actual music of a record at 
a disadvantage as compared with the original machine 
(having an external amplifier or trumpet), because 
the mechanical sounds of movement and friction are 
amplified with at least double the power that they 
need be. In effect, then, the self-contained gramo¬ 
phone yields but a mean proportion of the repro¬ 
ducible music of a record, largely “ diluted ” (as it 
were) with the unmusical complementary sounds of 
machinery in motion and of steel tearing a hard 
substance under the stress of friction. The would- 
be builder of a gramophone will do well to leave the 
hornless pattern severely alone if he would win 
the actual music of good records for his pains. 

The popularity of hornless models of late years 
may be attributable to the manufacturers’ assump¬ 
tion that the buying public has tired of the once- 
familiar appearance of the gramophone (or has 
become ashamed of its possession ?) and is anxious 
to disguise the thing somehow or other, even at the 
expense of many of its better qualities. Hence, for 
the modest purse, a self-contained form has been 





170 Something to Make 

devised which is more or less reminiscent of the 
cottage parlour musical-box of other days. Devel¬ 
oped from this inefficient thing (of little beauty) one 
finds the pretentious cabinet machine asserting itself 
to be a piece of drawing-room furniture of indefinite 
purpose ! For, after all, what do these shamefaced 
gramophones pretend to be ? Pseudo-Chippendale, 
Hepplewhite, Adam, pieces of what utility ? Cabinets, 
full of rare china or bijouterie, close locked up from 
sight—and why so ? Coldly, analytically observed, 
some of the ampler designs of these anomalous bits 
of furniture take on an almost furtive seeming, quite 
incongruous with their surroundings. 

The above generalities refer to several matters 
on which there appears to be much misconception, 
but the points particularly stressed in the interests 
of those who propose to build a satisfactory instru¬ 
ment are (a) avoid the hornless model, and (b) 
build substantially , recognizing at the outset that 
rigidity, solid mass and even passively inert weight 
are all factors of advantage in a gramophone. 

Cabinet-making, or rather carpentry, in hard 
wood of thick substance entails some hefty labour, 
a few reasonably good tools and some little patience, 
but these necessities must be faced if results worth 
working for are to be obtained ; (fret-workers, their 
methods and materials are “not on in this act!”). 
Mahogany, teak, walnut or oak, § in. thick, are 
optional woods; either of the two last are to be 
preferred, but undoubtedly they are tough to work 
upon. None of the softer woods (deals and pines) 
are worth making up for this purpose, excepting, 
perhaps, pitch-pine 1 in. thick. (Pitch-pine is the 











Mechanical Things to Make 171 

bold-grained, yellow, resinous wood much used in 
modern churches for pews, etc.) 

The simplest form and frame construction will 
serve quite well and therefore will be dealt with 
here, but of course those who have sufficient skill 
and a really good workshop will prefer to replace 
the plain carpentry suggested in the drawings with 
good cabinet-work having all the joints properly 
dovetailed, mortised, halved, or mitred and keyed 
together, as the case may be. However, if the wood 
be carefully cut and planed with edges shot square 
and true, butt-ended, glued, and screwed joints will 
produce a good solid job in well-seasoned hardwood. 

The machine to be described was specially 
designed for home workers, and has been successfully 
constructed by many amateurs, some of whom 
actually made every part, motor, sound-box, etc., 
inclusive, from accurate instructions worked out by 
the present writer for a contemporary mechanical 
journal. In the present brief article, however, no 
attempt is made to go too deeply into detail, mainly 
because finished metal parts of complete gramo¬ 
phones are now procurable. Quality varies with the 
price, too cheap sets are widely advertised, but these 
should be avoided as likely to cause much disappoint¬ 
ment, it being realized that good material and reliable 
labour are impossible to obtain to-day save at a 
fairly high cost. Choose, then, a fairly priced set of 
parts, stipulating for a worm-geared motor (which 
is preferable to the earlier cog-geared type) suitable 
for running one 12-in. disc, or two 10-in. discs in 
succession, easily , when the single spring is fully 
wound up. Note particularly that the machine is 






172 


Something to Make 


of the kind which can be wound up, noiselessly, 
while it is running , without in the slightest degree 
affecting the speed of the turntable. This permits 
the playing of selections continuously, and dispenses 
with the additional cost and elaboration of multi¬ 
spring motors designed to play half a dozen discs or 
more. A machine has to be wound up ; winding is 
less obtrusively done, little and often, by the operator 
while changing discs and needles. A long-run 
machine requires a long wind per dozen selections 
played through; all machines, large or small, will 
exact the same winding labour. Modern ‘ worm- 
geared ” motors are of admirably simple design, plate- 
framings being dispensed with in favour of a mono¬ 
block iron casting supporting the three axles of the 
spring-drum, turntable and governor; the great- 
wheel gears direct with the worm on the table-stem, 
another offset-gear operating the governor. This 
“ worm ” (screw or helical) drive dispenses with all 
cogged-gear and consequently the w T hole movement 
is smooth, steady and practically free from either 
sound or vibration. The mono-block casting has three 
or more lugs drilled for bolts by which the motor 
is substantially fixed either to the base or the top 
cover of wooden casing, according to the general design. 
The motor is screwed down in the centre of the case. 

Fig. 1, herewith, is a scaled sketch of the machine 
originally designed for amateurs who made every 
part by hand, but in all essentials the general scheme 
cannot be bettered for adoption by those who are 
now able to buy most of the finished metal parts. 
For example, the main casing c can remain unaltered ; 
it consists of a rectangular body or box 11 in. square 






Mechanical Things to Make 173 


by 6 in. deep, having top and bottom boards 12 in. 
square ; the whole being built of f-in. oak or walnut. 
The butt-end glued and nailed joints of the body 
are sketched at y , Fig. 2, and the cover and bottom 
joints at x in the same Fig., which is at double the 
scale of Fig. 1. Either the top or the bottom of 



the box must be made detachable (in order to give 
access to the motor), and this member should be 
secured by eight lj-in. brass wood screws passed 
through countersunk brass washers ; the fixed cover 
(or bottom) is best permanently attached by glue 
and screws (or nails, as used for the body joints). 
The tone-arm bracket b, shown as framed in f-in. 
oak, capped by the brass fitting b, will, in these days, 
be replaced by a finished iron casting. 









































174 Something to Make 

Similarly, the home-made tone-arm a, a2, and 
trumpet-elbow e, will be procurable ready-made* 
The form of compound tone-arm and swan-neck 
seen in Fig. 1 and again at Fig. 3, is strongly recom¬ 
mended in preference to any straight tone-arm ; its 
superiority subsisting not only in its mechanical 
convenience (when changing needles, replacing re¬ 
cords, etc.), but also in its refining influence on the 
sounds reproduced. The proprietary rights of this 
compound arm were owned originally by the Gramo¬ 
phone and Typewriter Company, whose gramophones 
and discs bear the brand, “ His Master’s Voice,” of 
world fame. The period of the patent, probably, 
has lapsed, but the peculiar advantage of this device 
over others remains. The trumpet or external horn 
h is of a form and dimension seldom met with nowa¬ 
days (except on old machines), but nevertheless its 
amplifying quality, no less than its fair rendering of 
average ranges of tone, has not been surpassed. The 
decorative “ flower ” horn (suggesting the form of 
a convolvulus blossom) was introduced early in the 
gramophone’s days, almost as much to the detriment 
of the machine’s tone as, subsequently, the “ internal ” 
horn has proved. The angle of expansion much 
influences the tonal efficiency of a horn, far more so 
than does its total size. Right-line (conical) ex¬ 
pansion more definitely determines the character of 
amplified sound than does curvilinear expansion, and 
the presence or absence of a “ flare ” (curved trumpet- 
mouth) has been proved to be rather an adjunct of 
suggestive appearance than of tone-modification, in 
gramophone practice. Although no definite angle 
of conical expansion can be cited as the best possible, 







Mechanical Things to Make 175 

it is certain that so little as 5 degrees of variation 
either side of an established normal will much affect 
results. The angle of the flareless horn shown in 
Fig. 1 is 18 degrees, which represents a satisfactory 
compromise between a minimum of 15 degrees and a 
maximum of 20 degrees, a contraction of the former 
tends to produce muffled tones while expansion 
beyond the latter angle promotes blatancy. The 
horn is 24 in. long, 2 in. in diameter at the socket, 
and 9 in. at the mouth. Stout-gauge tinplate (or 
tinned steel) is one of the best all round materials 
for a horn of this or a larger size; so far as tone is 
concerned tinned iron is better than brass, copper 
or aluminium, although any of the latter are more 
decorative. Fig. 4 is a dimensioned plan from which 
the tinplate can be marked out; the sheet of tinned 
steel required will be 25 in. by 30 in. It should be 
drawing-pinned round the edges to the bench or 
floor, the arcs a and a being struck with a scribing- 
point attached by a string 
to a bradawl or nail 
driven into the centre- 
point pc , the radii y and 
z being drawn with a 
straight edge. The J-in. 
margin m, seen beyond y , 
is the tap for the soldered 
seam. After roughly 
rounding-up, this seam is 
run with a hot bit and 
plenty of zinc chloride 
flux, the work being sup¬ 
ported on a wooden bar 



• * 
» » 

\ • 

Fi*. 4 











176 Something to Make 

run through the horn ; while soldering, the seam is 
pressed down on the supporting bar with another 
piece of hardwood. After seaming and washing free 
from acid flux, the shaping of the cone may be finished 
by endlong rubbing on the supporting-bar (a broom¬ 
stick) with another piece of rounded wood. Avoid the 
use of either hammer or mallet; the “sleeking” 
method produces a smooth, undinted cone. A bell-flare 
may be added to the trumpet if desired, a small tinplate 
washbowl serving admirably. The bowl’s bottom 
should be marked with a circle slightly smaller than 
the horn-moutli and cut out with shears. The horn, 
slipped through this, should project about J in., 
after soldering, the projecting edge may be neatly 
hammered down and re-soldered inside the bowl. 
Enamelling the horn outside, and the bell inside and 
outside, improves the appearance and somewhat 
modifies the crisp resonance of the tone. 

Fig. 5 is a cross-section of one of the best forms 
of gramophone sound-box yet produced. Although 
its construction may be beyond the scope of most 
readers of this book, its complete details are given 
in order to impart a full understanding of this vital 
unit of the machine—actually and literally the 
“ source of its voice.” 

The body b is of solid brass; to the front of this 
is attached the ring r, by three small screws (not 
shown). Clamped between the ring r, and the 
body b is the mica diaphragm d, but the mica does 
not touch the metal of the cell at any point, being 
insulated from it by the two rubber rings or “ gaskets ” 
g, between which the diaphragm is firmly nipped 
when r and b are screwed together. At the bottom 





Mechanical Things to Make 177 

of the ring r, is rigidly attached 
a brass plate extension e, 
provided with two tapped 
holes for the tension-screws 
(which are seen passing through 
the flat steel springs ) and also 
the knife-edge projections k, 
on which is pivoted the needle- 
socket and plate n. The 
needle-socket w, its baseplate 
w 1 , and the diaphragm-finger 
/, form one solid unit in 
themselves which is quite in¬ 
dependent of the body b , and 
the ring r, but which is 
pivoted upon the knife-edges 
k f and maintained in position 
by the two tension-screws 
passing through the two springs 
s, s 1 (which are riveted to the n baseplate). The n> n 1 , 
f fitting, therefore, is, as it were, saddled upon the 
knife-edges k , by the stiffly sprung connexion of the 
tension-screws. The needle-socket, therefore, has a 
much restricted but definite rocking movement on the 
knife-edge pivots which permits it to push upon or 
pull against the diaphragm d, to which the finger / 
is attached by the nutted screw in its centre. Hence 
the infinitely rapid to and fro vibrations of the 
needle-point in the sinuous groove of the record are 
imparted direct to the centre of the diaphragm d , 
through the n—j fitting, while the main body of the 
sound-box remains practically inert. It has been 
explained that the diaphragm is rubber-insulated 



L 
























































178 Something to Make 

from the mass of the body by the gaskets g t but the 
body as a whole is also cushioned from the tone-arm 
and the rest of the machine by the stout rubber ring 
i. This ring is attached to the body b by the two 
large screws shown, and cemented within it is sup¬ 
ported the short brass tubular socket i , which fits 
on to the tone-arm. (It will be observed that the 
socketing-tube /, does not bear directly against the 
metal of the body.) 

The sound-box here described is not a new model, 
but it is as yet unsurpassed in all-round efficiency. 
It must be admitted, however, that the design is 
somewhat elaborate and expensive to produce. 
Many simpler constructions exist and perform fairly 
well even although the best tonal results are not 
perhaps obtained. In selecting a sound-box the 
actual desiderata should be borne in mind for com¬ 
parison, point by point, with the article under ex¬ 
amination. They may be better appreciated by 
consideration of the salients in the first-class design 
here illustrated ; these are obviously as follow :— 
(a) The body is a machined casting of solid substance 
within which the flexible diaphragm is free to vibrate 
through the leverage of the finger bar. (b) The 
diaphragm is cushioned from immediate contact with 
the solid mass of the metal by the gaskets g. (c) 
The whole body of the sound-box is cushioned from 
the tone-arm (and thus from the total mass of the 
machine) by the insulating rubber i. Hence it should 
be seen that the sensitive mica drum-head will act 
to the best advantage when supported in the midst 
of a heavy and inert mass of solid metal, itself in¬ 
sulated as far as possible from all rigid connexion 





Mechanical Things to Make 179 

with adjacent metal, woodwork, or other substance 
subject to tremor or vibration. 

Throughout this brief paper the points most 
urged upon those who contemplate building a gramo¬ 
phone (or improving the performance of an existing 
one) have been solidity of construction and adequate 
cushioning of the units of mass from mass. The 
motor lugs, then, should be seated on rubber washers 
interposed between them and the wooden casing, 
the bolts or screws also having rubber washers be¬ 
neath their heads. All the axles and gears should 
be without shake; the various connexions of the 
tone-arm should be as free from looseness and rattle 
as care can make them. Lubrication is important 
and (indirectly) can be employed effectively towards 
the suppression of vibration. To this end no thin, 
limpid oil should be used anywhere, but at all work¬ 
ing parts the lubricant should be of a viscid character, 
yet one which will not become gummy with age. The 
best possible lubricant for gramophones is a smooth 
mixture of unscented vaseline and pure graphite 
powder. Graphite, plumbago, or blacklead are 
one and the same substance (a pure form of carbon 
nearest to the diamond,which is crystallized carbon). 
On no account must household blacklead be employed ; 
the pure, impalpable gritless graphite is procurable 
from any druggist (to order if not kept in stock). 
Mixed vaseline and graphite never hardens or gums, 
its clinging consistency keeps it in contact with all 
slow-moving gears, hence it rarely needs renewal. 
Its bland smoothness almost eliminates bearing- 
friction, while its viscosity subdues the rattle of loose 
parts. Plain vaseline serves well to mute possible 







180 Something to Make 

vibration in the articulated joints of tone-arms (see 
j t Fig. 1) and also the pipe-socket of the swan-neck 
articulating a and a 2 . (While using ample lubricant 
as directed, care must be taken to keep all grease 
from the surface of records, or they may be softened 
and destroyed.) 

Speed regulation should be carefully attended to 
from time to time, or a machine may be found to run 
insensibly faster with age. Needle-discs of most 
brands are run at 75 revolutions per minute, and 
stylus-discs (such as the Pathe) at 90 revolutions per 
minute. To time the turntable scribe a radial line 
across a worn-out record and run this on the machine. 
The scribed line will cause a distinct tap at each 
revolution ; check the tapping by a watch ; a needle- 
disc should emit 25 taps in 20 seconds, and a Pathe 
disc 30 taps in 20 seconds. Brush out the grooves 
of records before and after use with a brush of pliant, 
fine bristle. Very much worn, harsh-playing records 
can be rendered more tolerable by dusting with 
French chalk powder and afterwards dusting off 
with the brush. Employ only the best needles (hard 
or soft tone) and never use a needle twice. When 
putting the machine aside let the motor run nearly 
down (not completely so), this tends to preserve the 
elasticity of the spring. Gramophones undeniably 
develop “ moods ” from time to time, which sometimes 
are quite unaccountable, even by an expert, but more 
often defective tone is traceable to one or more 
sources which can receive prompt attention by any¬ 
one wdio has taken the pains to understand the 
instrument. It is hoped that this paper will assist 
its readers in this direction—for example, if the tone 







Mechanical Things to Make 181 


suddenly falls off in strength and becomes thin and 
harsh (although a record of known quality is being 
played) one would first examine the sound-box to 
note if the gaskets are nipping the diaphragm tightly 
(as they should do). Perhaps they may have per¬ 
ished or hardened with time and require renewal. 
The diaphragm-finger (/, Fig. 5) may be loosened 
from the mica ; it must be nutted tightly again and 
further secured with a speck of hard beeswax run 
in with a hot wire (or seccotine will do). Jar and 
rattle of the tone-arm joints enfeebles tone besides 
causing displeasing sounds. A dressing of pure 
vaseline (well wiped off externally) will usually silence 
this vibration. Tone periodically going flat may 
indicate insufficient lubrication of the motor, or (at 
the worst) a bent axle in the same, but sometimes 
flatness results from the slip of the record on the 
turntable; in such cases a brisk brushing up of the 
nap of the baize covering of the table arrests slip ; 
if not, the centre bole of the disc may be lightly 
packed with paper to give the peg a slight grip. 

Defects should be corrected as they occur or they 
may lead towards troubles less easy of remedy. 

However, it is thought that a glance through this 
brief summary of a large and interesting subject 
will at any time assist in the tracing and eventual 
remedy of otherwise obscure faults, even as it may 
provide a working basis for the actual making of a 
gramophone. 









A CRICKET SCORE BOARD AND 

NUMBERS 


T HE cricket score board shown by Fig. 1 may 
be about 6 ft. 6 in. high altogether, the board 
itself measuring 1 ft. 8J in. by 2 ft. Fig. 2 shows 
how the feet are made, a square hole being cut to 
receive the post. 

The latter, shown in Fig. 3, is trimmed at the 
bottom to fit the hole in the feet, and a portion 
is also cut away at the top to receive the board. 
All joints should be a good fit, well glued and nailed. 

The board may be 
| in. thick, and may 
be either screwed 
on, or provided 
with two bent iron 
loops, as in Fig. 4, 
so as to be readily 
detachable. 

The space on 
the board is divided 
into three by J-in. 
strips of wood, over 
which wider but 
thinner strips are 
nailed, to hold the numbers in position. 

In Fig. 5, a indicates how the top and bottom 
strips are made, while b shows that the two middle 
thin strips require to be slightly wider. The movable 
numbers are best painted in white on black card¬ 
board, 6 in. by 4 in. 

182 

















Section III.-SIMPLE MODEL MAKING 


HOW TO MAKE A DISTINCTIVE TYPE 
OF MODEL AEROPLANE 

| N designing the model aeroplane described in this 
article, it has been my aim to produce a machine 
which shall be strong and capable of flying a good 
distance. I made a rather large model aeroplane 
about three years ago, which, in spite of its size, 
stood a good deal of knocking about, but if you 
build the machine I am about to describe, carefully, 
it should be almost as strong again as the older 
model—much has happened since 1919. 

For some time past I have been collecting data 
concerning the long flight model aeroplanes of 
Britain and America, and have been particularly 
struck with the designs of two American machines. 
As these models have been well tested and as their 
designs are the result of much patient study, we 
should at least consider them before we begin to 
build. It is interesting to note that all the success¬ 
ful models have twin screws and a triangular main 
frame, and the monoplane type is chosen for speed and 
duration of flight. The usual length of the main 
frame of nearly every model on my list is 34 in., but 
the size of the planes varies very much. 

To begin with we cannot do better than make 
our model 34 in. long, but the other dimensions we 
must work out for ourselves, as I do not think it 
advisable to ask you to build so extreme a machine 

183 


184 Something to Make 

as the best of the American models, which measured 
only 17 in. across the main plane. Below I give 
three examples of fast, long distance flyers—the 
dimensions will interest you. 


No. 1 (American) 

Length. 

34 in. 

Width across 
plane. 

24 in. (by 3j in.) 

Width, 

elevator. 

9J in. 

No. 2 (British) 

35 in. 

24 in. (by in.) 

8 in. 

No. 3 (American) 

34 in. 

17 in. (by 4 in.) 

7 in. 

No. 4 (American) 

34 in. 

18 in. (by 3 in.) 

8J in. 

Most of these 

aeroplanes were record breakers, 


but, if you were to build a model on the lines of any 
of the American machines, I doubt whether you would 
get good results, because naturally an amateur can¬ 
not run things quite so close to the workable mini¬ 
mum as an expert could. To be on the safe side I 
advise you to build your machine to the following 
dimensions: 

Length. Man Plane. Elevator. 

34 in. 24-25 in. (by 6 in.) 8 in. (by 3j in., at 

narrowest part). 

You can begin by making the main frame, using 
either very thin bamboo or birch wood ( T ^ in. by 
J in. square were the dimensions used on two of the 
best American machines). I will, first of all, how¬ 
ever, deal with the bamboo frame type. 

“ Garden canes ” are the best kind of bamboo 
rods for this purpose, but they vary in weight. See 
that you get light ones, not tapered too much, and 
(about) J in. in thickness. Please remember that 
they must be very light and not too pliable. 

For the frames of the planes birch must be used 








Simple Model Making 185 

•—this should be in. thick, and for the main plane 
the strips should be roughly about J in. wide. Work 
down the width of all frames and struts as much as 
you can without weakening the model. Please refer 
to Sketch 1, Working Plan, and Sketch 1, Scale 
Plan, for the general details of the frame. The 
American machines take the triangle out to a sharp 
apex, but I suggest that you get some cane (real 



Scale Plan 


cane, not bamboo) and make a rounded buffer end— 
for fixing which study Sketches 9 and 10, Working 
Plan, of which more anon. 

Lashing is resorted to very freely in making these 
aeroplanes, in order to avoid splitting the wood— 
use stout thread (or thin water cord) and afterwards 
soak it with varnish or cycle enamel. The planes 
should be cambered as shown on Sketch 2, Scale 
































186 Something to Make 

Plan. In order to curve the thin wooden frame- 
strips, first soak them in water, then hold them over 
a gas jet turned down as low as possible. Allow 
the flame just to touch the wet wood, but do not let 
it get charred. 

Aeroplane nails are generally used for fastening 
the frames, but even they sometimes split the wood. 
I have a device of my own—I use stout (black) pins—- 
push them through the wood-strips and then coil up 
the pointed ends with a tiny pair of round-nosed pliers. 
My 6-ft. model yacht was held together in this way. 

I have chosen the turned “ backwings,” partly 
because I think they give better results than the 
ordinary type, and partly because they look rather 
well—square ends will do nicely, however, if you 
cannot manage the curving. 

For every detail concerning the making of the 
. planes and the elevator see diagrams. On the Scale 
Plan, Sketch 5 shows how the tips of the “ wings ” 
are to be turned up. Cane tips should be used (for 
the method of fastening them with thread lashings 
use thin water cord if you like) and coiled pins can 
be seen on Sketches 2 and 8, Working Plan. Look 
at the model aeroplanes sold at shops, you will see 
how neatly this lashing is done. Well lashed and 
cross-fastened with the pins the wood will break 
before the joint gives at all. For the fitting together 
and general construction of the main plane please 
refer to the Working Plan, Sketches 4 (method of 
fastening the cross-pieces), 1 (general construction), 
3 (end of frame) and 8 (side view of tip). 

The frame of the elevator might be made in a 
similar manner, but steel wire could be substituted 







Simple Model Making 187 



for cane at the tips. It should be bent into a V, as 
shown on Sketch 4, Scale Plan. With the fixing of 
both the main plane and the elevator I will deal 
towards the end of this article. 

Note the cross struts on the main frame (Sketch 1, 
Scale Plan), also the thin bracing-wires—these must 
be made of strong but light wire. 

Before I refer to fitting, covering, and adjusting 
the planes, I must deal with the propellers and the 
“ engines,” 

I take it that you have now made the frame, 
and the frames for the main plane and the elevator, 
but if you do not find that you can buy suitable 
bamboo (for the triangular main frame) in your 
district, try wood—pitch pine is sometimes used for 
what I term the “ back-bones.” Clearly understand 
me, birch for the plane frames, pine for the main 















































































188 Something to Make 

frame (the part shaded deeply on Sketch 1, Working 
Plan). The sizes used on the two American machines 
were J in. square, and J in. by T 3 g in. Possibly you 
should exceed these figures slightly, but, remember, 
lightness is everything in aeroplane construction. 

I strongly advise you to buy the propellers (8 in. 
and 6J in. are sometimes used) ; they are sold quite 
cheaply. I have made propellers in three different 
ways, but if you want your model to fly a good dis¬ 
tance, buy these fittings ready made ; for you simply 
cannot make them as well as a professional maker 
would. Get two 8-in. propellers and a few collets— 
mention that you are using twin screws . Now glance 
at Sketch 2, Working Plan. Here you have one of 
the bearings. If you can get fairly thick aluminium 
(odd strips will do), make each bearing of a single 
piece of metal, but if it is inclined to hend under pres¬ 
sure, double it. You will risk splitting either bamboo 
or wood if you try to use screws, so follow the plan 
shown on Sketches 2 and 5, Working Plan. Drive 
two or three strong black pins through the bearing 
and the end of the frame (binding it well if composed 
of bamboo), coil the ends, then lash the bearing very 
firmly with thin water cord as shown, after which 
fairly soak the cord with varnish or cycle enamel. 

Note the way in which the propellers are to be 
fitted—c shows the position of the collets. Eight 
or ten strands of aeroplane strip (elastic) will be 
needed for the “ motors ” ; tie each loop tightly 
with water cord. Note the hooks for the forward 
end of the loops (Sketch 10, Working Plan) ; an 
alternative plan of making the hooks is shown on 
Sketch 1, Scale Plan. I strongly suggest the lashed 









Simple Model Making 189 

plan (10); notch the frame very slightly so that the 
lashing does not slip, and varnish it well. 

Now, with regard to the elevator, it would be 
possible to make the frame of steel wire with several 
cross-pieces, or you may build it as you did the 
main frame, only make it much lighter. The steel 
wire plan is perhaps the best; any cross pieces woula 
be kept in place by the fabric when stuck over the 
frame. 

Please note the beautifully simple American 
device for fastening the elevator to the frame with 
one strong elastic band (see r, Sketch 11, Working 
Plan). The elevator gets a lot of rough usage, and, 
if fastened as shown, naturally it gives when knocked. 
It is easy to adjust too, if a couple of wedges like 
the one shown on Sketch 12 are fastened to the 
frames. By pushing the elevator forward greater 
elevation is obtained. 

Unless I know the weight of your propellers and 
the materials you have used, the position of the 
main plane cannot be given exactly. Experiment 
by roughly fixing the main plane with string or elastic, 
then move it backwards and forwards until your 
machines glides perfectly, when set off by hand 
alone. Then try it under “ its own power ” until 
you get a very nice balance ; success or failure will 
depend to a great extent upon getting the main plane 
exactly in the proper position. 

Now, whether you have used wood or bamboo 
for the “ backbones,” fasten the main plane to them 
by means of strips of aluminium fixed as shown on 
Sketches 6 and 7, Working Plan. Plenty of “ play ” 
must be allowed at x, Sketch 7, so that the plane 




190 Something to Make 

can be moved about for experiment, but finally fix 
it firmly by taking a pin, or thin screw through the 
centre. Remember there will be four of these attach¬ 
ments ; all of them are to be finally fixed in the same 
way. 

To avoid using flimsy and unsuitable material 
for covering the planes, I advise you to get model 
aeroplane fabric, obtainable at any model shop. 
This should be stuck to the frames with liquid glue ; 
give a good overlap—on the underside, of course. 
If you have the “ curved back ” planes shown, I 
think it would be a good plan to use separate tips 
on the main plane—the tips will be the “ tricky ” 
part—experiment with ordinary cloth or paper 
before you fix the fabric ; a little snipping will some¬ 
times work wonders. 

Many people wind up twin screws with an egg- 
beater, and for long distance flights a lubricant for 
the rubber is used—this can be obtained at any 
aeroplane shop. 

Now there is a very interesting experiment you 
can try if you like, but make this attachment so that 
it can be removed quickly. For short speed flights 
you might get a little extra pace by fitting a much 
smaller third propeller, at the point indicated by 
the dotted lines (Sketch 1, Scale Plan). This pro¬ 
peller should be much smaller than the twin screws, 
and might have half the power of elastic. It won’t 
do for long flights, but probably you will like to 
experiment in this way. The idea is novel, but do 
not take this attachment as a permanant part of the 
machine. A third screw, small, very light and fast 
going, should add to the speed over short distances, 





Simple Model Making 191 


but it has its drawbacks and will probably affect the 
steering. Please yourselves as to whether you make 
the experiment. 

Such a model can be made cheaply, but once 
again let me impress upon you that the flight and 
the duration of flight will depend upon the care with 
which you make it, the trouble you take over the adjust¬ 
ment , and the free and even working of the propellers. 

The propellers should stand winding quite 800 
turns with safety. Sketch 3, Scale Plan, needs no 
explanation. 


A HANDY GLASS-CUTTER 



VERY effective glass-cutter may be made from 


\ the broken end of a fine square-section file, taper¬ 
ing from about in. to -/,■ in. A piece about 1 \ in. 
long will do. Cut off 3 in. of round curtain rod, 
about f in. diameter, for a handle, make a hole in the 
end with a small bradawl, and push the piece of file 
in. Do not knock it in, or the cutting edge will be 
injured. One of the angles or corners at the end 
of the file is used. On drawing this along the glass 
with gentle pressure a fine line is scratched, and the 
glass promptly snaps across if bent smartly from 
the other side. 













HOW TO MAKE A MODEL CIGAR BOAT 


S OME time ago there were two cigar-shaped 
boats in Southampton Water, and they attrac¬ 
ted much attention. Vessels of this type are very 
fast craft, and a model built more or less in the 
form of a cigar should be able to defeat any boat of 
her length; therefore I propose to give instructions 
for making a novelty of this kind. 

Your boat must be built in two sections, so 
decide first of all whether you will lay the halves 
one upon another, or place them side by side. Pos¬ 
sibly the upright method (shown on Sketch 2) is the 
best, so get two pieces of soft wood, 28 in. long, 4 in. 
deep and 2J in. or 3 in. wide. The shape of the boat 
is shown on Sketches 1 and 4 ; nail or screw vour 
wood together after roughly shaping out the sections 
with a big pocket or “ Jack ” knife, then finish off 
the joined up hull with a spokeshave and a small 
plane. 

Having got the hull finished except for the final 
smoothing off, carefully hollow out your sections 
with a small gouge, taking care not to damage the 
pointed ends. The best way to join the halves to¬ 
gether is to use screws at the ends where the wood 
is fairly thick and then use two or three dozen 
long black pins along the seams. Drive the pins into 
the wood on a slant—if they go right through both 
sections clinch them back into the wood. 

The fin (Sketch 3) is just a piece of thin galvanized 
iron ; ask the ironmonger to cut it to shape for you, 

192 


Simple Model Making 193 

lie will do so in a few moments with tinman’s shears. 
Note the flaps at the top, bend the first to the right, 
the second to the left, and so on, then, if you bore 
the flaps, the fin can very easily be screwed to the 
bottom of the hull; take the greatest care to see 
that it comes in line with the ends of the model. 

Possibly you are not a good hand at melting and 
casting lead, but with this boat you can, at a push, 
do without any melting. Get a few pounds of sheet 
lead—probably your boat will require 3J lb. of bal¬ 
last when it is trimmed, so buy 4 lb. Cut the lead 
in strips, the length of the fin, and about 3 in. wide 
(it is to be folded), then, by bending these strips 
round the fin and fastening them in position by 
driving shortened nails or screws through both lead 
and fin (punch the holes out first), you will have a 
rough keel which can be cut and pared into shape 
with a spokeshave or small plane (don’t put the nails 
where the plane is likely to go). A rasp is very use¬ 
ful in shaping a lead keel. 

It is best to put a little flat deck on the top of your 
“ cigar ” ; leave the bottom of the boat under the 
mast thick enough for a “ step,” or hole, for the heel 
of the mast. Do not bore this hole right through 
the boat, get some pointed piece of metal into the 
hull after the halves are joined, and gradually 46 work ” 
the step deep enough. 

All the spars should be made of “ garden canes ” 
(bamboo), sold at two for a penny, and the sails 
should be of thin close stuff. The sails are—the jib 
( j), No. 2 jib (j dotted lines); mainsail (m). The 
spars are— b (on Sketch 6) the boom, b (on Sketch 4) 
the bowsprit. 

M 










194 


Something to Make 



The Hull .—Length 28 in., breadth 5 in. or 6 in., 
depth of hull only 4 in., depth with fin (total) 8 in. 
for a sheltered lake, 10 in. for a very open lake. 
The length of the fin should be about 1 ft. 

Spars and Sail .—The boom (b Sketch 6) should 
be about 18 in. long and the bowsprit (b Sketch 4) 
10 in. The total height of the sail plan (deck to tip 
of mainsail yard) should be 36 in. for a sheltered 
pond, but for sailing on any kind of open water, cut 
down the height several inches. 

For this type of model a rudder, which should be 
weighted, is needed only when running right before 
the wind, on other points of sailing remove the 
rudder, the boat should balance with her two sails. 
If she is inclined to fly up in the “ eye ” of the 
wind, lengthen the bowsprit (b on 4), but if she 
runs off with the wind almost behind her, shorten it. 

Smooth the hull with glasspaper before painting. 






































HOW TO MAKE A MODEL 
TRANSPORTER BRIDGE 


M ANY boys declare that they want something 
new in the way of models, and to these 1 
would say, “ Why not make a transporter bridge ? ” 
At some of our ports engineers have been unable to 
build ordinary bridges over the rivers or harbours 
because ships with high masts are constantly passing 
up and down, so they have devised what are called 
transporter bridges. On these structures a kind of 
trolley, from which hangs a big car, is hauled back¬ 
wards and forwards by means of cables and electric 
motors. It is possible to make a very pretty little 
model of one of these bridges for about a couple of 
shillings, and the trolley can be worked by means of 
two simple clastic motors. 

Although I have drawn this model to scale you 
can, of course, please yourself as to how long you 
make it. I have, for want of space, been obliged 
to depict rather a short bridge, but there is no reason 
why you should not make a much longer one. Settle 
this important question, then get two long, smooth 
pieces of wood, about an inch and three-quarters wide 
and, say, half an inch thick. These are for the 
upper girders (see Sketch 1, Scale Plan). For the 
uprights of the suspension bridge and the four sup¬ 
ports you will want some round wooden sticks— 
these you can easily cut for yourself—and a supply 
of non-rusting wire (two thicknesses). None of these 
materials should cost more than a few pence, but 

195 


Something to Make 


196 



you will want some kind of support or foundation 
upon which to build your model. 

You w T ill notice that I have drawn two piers, 
with water between them, and if you can get tw r o 
solid w r ooden blocks for this part of the model, I 
strongly advise you to use them, for their thickness 
and weight will be very useful. Rather shallow boxes 
turned upside down would do, but they look rather 
clumsy. 

Now before you can fit the long upper girders, 
you must make the four trellis-w r ork supports. This 
is quite a simple job if you have a nice firm founda¬ 
tion. For each support cut out, round, and smooth 
off four little sticks, all of exactly the same length, 
then bore four holes in your block just where you 
find that this particular support will have to be 
placed. Now study Sketch 2, Scale Plan, and Sketch 

















































































































Simple Model Making 197 

1, Sketch Plan, and you will see how these four sticks 
are to be driven into the holes in the block, so that 
they form one of the uprights which is roughly a 
pyramid. All four of the supports must be made in 
this way; then, by boring holes in the top girders, 
marked g on the plan, you can gather the upper 
ends of each support into a kind of bunch, and thrust 
them into these holes, which must, of course, be 
made large enough to receive them. If some strong 
glue is first poured into the openings the tops of the 
supports will be very firmly held in their places. 
Be sure that all the supports are of the same length 
and that the upper part of your bridge is quite level. 
The braces of cross-pieces, which on the full-sized 
bridge are of great importance, can be represented 
on your model by a few lengths of wire, crossed as 
shown on Sketch 1, Sketch Plan. All the braces 


























































































198 Something to Make 

and thin cross-braces on the model can be made of 
wire, for, of course, we only want them so that our 
bridge shall look the “ real thing.” The use of wire 
simplifies the making of the upper part of the model 
very much, as wire can be bent round and twisted 
with pliers quite easily. 

Just glance at Sketch 5, Sketch Plan. The main 
upright (u) can be made of wood, but the remain¬ 
ing posts should be composed of thick wire ; the 
connecting rail (w) is of no great importance, any 
thin wire will do for this. Holes must, of course, be 
bored in the long girders, into which the ends of the 
uprights should be thrust and then glued in position. 
See that the uprights are placed on the outer edges 
of the girders —as shown on Sketch 1, Scale Plan— 
otherwise they will interfere with the trolley railway. 

It is advisable to make the trolley and the hang¬ 
ing car before beginning the little “ tramway ” on 
the top of the girders. On Sketch 2, Sketch Plan, 
you will see a very simple mode of making the trolley. 
The base (grained) is just a piece of fairly thick wood, 
to which two side pieces (white on sketch) are to be 
screwed. Four of the little grooved wheels which 
are used for blind cords should be bought at an iron¬ 
monger’s, they are just the thing for fitting on to 
your “ tramway.” There need be no difficulty about 
fitting these, for four fairly long, thin screws, taken 
through the central holes of the wheels and into the 
wooden sides of the trolley, will 44 do the trick.” 
Two small screw-eyes should be placed at each end 
of the trolley, as shown on the sketch, to receive 
the 44 Cables ”—of which more later on. 

As your car will be quite small I should advise 





Simple Model Making 199 

you to make it of a block of solid wood, painting in 
the windows, etc., as shown on Sketch 3, Sketch Plan. 
A number of the smallest screw-eyes you can buy, 
placed along the top of the car to receive the sus¬ 
pending ropes, will make your car look “ important ” 
—it is supposed to weigh several tons, you know. 
Thin water cord or flower wire will do for the suspen¬ 
ders ; the wire looks rather better than the cord. 

Having made your trolley you may begin the 
“ tramway ” on the top of the girders. I wanted you 
to make the trolley first because it is easy to move 
the rails a little, but not very easy to alter the trolley. 
Of course, you must see that all four wheels are 
exactly in line; that is, each pair must be directly in 
line with the other. Small washers, made of tin 
or leather, might be placed on the screws to keep the 
wheels from rubbing against the wooden sides of 
the trolley, and, if the wheels themselves are out of 
line, a little tightening or loosening of the screws will 
adjust them. The “ tramway ” is shown clearly on 
Sketches 2 and 8, Sketch Plan ; it is just a couple 
of thin battens screwed to the girders with the smal¬ 
lest screws you can buy ; the heads of these screws 
must either be slightly let into the wood or filed flush 
with the top. The width of the “ metals ” must, of 
course, be governed by the width of the grooved 
wheels you use. 

Now you want either one or two “ motors ” to 
haul your car to and fro. I say that you want either 
one or two motors, because one can be made to do the 
work, but perhaps you may like to have two. 

The sketches on the Scale Plan will give you some 
idea of how the “ cables ” haul the car to and fro, 





200 Something to Make 

and Sketch 6, Sketch Plan, shows a very simple 
“ motor ” which I have devised to do the hauling. 
The “ drum ” for coiling the “ cable ” can be made 
out of a large-sized cotton reel painted. Through 
the middle of this reel a wooden plug must be placed, 
butted at one end, so that it can be driven into the 
hole until it is jammed in position. A baseboard 
of wood is now to be made for the motor and uprights ; 
the latter should be of thick tin or zinc (three of these 
are shown on Sketch 6, Sketch Plan) and screwed 
to the board. 

If you have hammered the wooden plug into the 
reel or “ drum ” (as shown on Sketch 7, Sketch Plan), 
a long thin screw at one end and a screw-eye with a 
very long thread at the other will fasten the “ drum ” 
to the framework very nicely (see Sketch). Now 
slightly open the eye of the inner screw with pliers 
and you have a fine fixed hook all ready to take your 
loops of elastic. As you will not want to be con¬ 
tinually turning the “ drum ” to wind your motor, a 
winding handle must be placed at the inner end of 
the apparatus. A piece of thick brass wire, bent as 
shown on the sketch and kept from rubbing the 
frame by means of one or two little washers of leather 
or a tiny nut threaded on to the wire, is all the wind¬ 
ing apparatus you need. But after you have wound 
your motor it is obvious that, unless you block your 
winding handle, it will fly round when released. 
The little blocking strut, shown on Sketch 4, Sketch 
Plan, is so simple that I need hardly describe it. 
Any piece of fairly thick metal will do for the arm, 
which must be screwed to the baseboard so that it 
moves very stiffly. The dotted lines show the arm in 







Simple Model Making 201 

a blocking position. Possibly it would be as well to 
have a brake of this kind for the “ drum ” too. 

It will be better, perhaps, to have two motors in 
the place of one. By an endless band you could do 
with one, for, of course, the motor can be wound 
either way. With two motors, one at each end of 
the model, first unhook one “ cable ” (see 1 , Scale 
Plan), then wind and release the motor that is in action , 
and your trolley-car will cross the bridge. To make 
it return unhook the motor that has just been at work, and 
“ hitch on ” and wind the other ; when this is set going 
the car will return. 

Paint your model with enamel—a “ dead ” grey 
looks well. 

Hints. —The rubber should be made into loops 
and slipped over the hooks. Just how many loops 
you will require depends on the size of your model. 
“ Aeroplane strip,” obtainable at about one penny 
per foot (any rubber shop), is the best kind of elastic 
to use. 

Weights descending from high poles might be 
made to work the model, but rubber motors take 
most boys’ fancy. 

On the diagrams s stands for screw-eye, t for 
trolley, w for wire, g for girder, and h for one of the 
holes in the foundation. 










HOW TO MAKE AN EXISTING MODEL 
BOAT SELF-PROPELLED 


M ANY boys cannot build the hull of a boat, but 
they long to own something that is self- 
propelled. Most lads have a model yacht of some 
kind, however. Usually this long-suffering craft is a 
sailing cutter of the old type, similar to the one 
depicted on Sketch 1. “ But what can I do with 

my old sailing boat ? ” you ask. “ I should have to 
wrench the mast and sails out of her before I could 
make her into any kind of motor-boat.” You need 
do nothing of the sort ; make her into an auxiliary 
“ motor ’’-boat—it will cost you about one shilling 
to do so. 

It does not matter very much whether your boat 
is exactly like the one I have depicted ; I chose the 
old style because it is the ordinary or standard type 
of craft sold at the model shops, but almost any kind 
of sailing boat will do. To begin with you must 
cut through the keel and the “ dead wood ” (d) near 
the stern. As the deadwood may split during this 
process, make the L-shaped piece of zinc or brass, as 
shown at d, Sketch 2, and screw it to the deadwood 
before you begin cutting the propeller recess. The 
lower end of this piece of metal is to be bent round 
and screwed to the other side of the deadwood to 
form the bearing (see b, Sketch 3). 

Having cut the recess for the propeller, commence 
to make the inner bearing (i, Sketch 2) and screw 
this to both sides of the deadwood, Now get a nice, 

202 


Simple Model Making 203 

fairly thick piece of wire (brass), but before pro¬ 
ceeding to make the propeller-shaft (see Sketch 4), 
put the yet unbent piece of metal through the bear¬ 
ings, which should be squeezed in with pincers until 
the shaft just moves freely, but cannot wobble 
about. Note, however, that it must move quite 
freely. 

Tin or brass is the best metal to use for the pro¬ 
peller. Cut out the shape as shown on the diagram, 
and at the exact middle bend or hammer out by 
beating a piece of wire upon it the little kink or 
recess shown near s, Sketch 4. As it is important 
that the shaft should be firmly, evenly, and properly 
attached to the propeller, get a tinman to solder it 
into the little recess, as shown at s, Sketch 4. 

You must, of course, slip the shaft through the 
bearings before you coil one end, and make the hook 
at the other end of the wire, but (this is most impor- 























































204 Something to Make 

tant) a small collet or washer b must be put on to 
the wire before any coiling or bending is done. This 
little washer is, of course, intended to keep the loop 
or “ eye ” clear of the bearing ( see just below b, 
Sketch 3). 

The great difficulty with most boats not intended, 
when first built, for “ motor ’’-boats is that they are 
too short upon the keel, and, therefore, no great 
length of rubber can be used if the ordinary method 
is followed. I have devised a way of getting over 
this difficulty by first taking the rubber along below 
the keel, then upward through a large brass screw 
eye ( see Sketch 2, forward end of the boat). After 
passing through the eye, the rubber is to be taken 
bach along the keel, see R R (return rubber). 

Note how the propeller is to be bent—this is 
very important. Three or four strands of “ aero¬ 
plane ” rubber, or two pieces of J-in. square rubber 
should be used for the motor. Possibly for this 
type of rubber “ motor,” which is different from the 
usual kind used on model aeroplanes, &c. (for the 
rubber “ returns ”), the J-in. strip will be best. 

The coil or “ eye ” at the after-end of the propeller- 
shaft is to help you to wind up the rubber, for, with a 
recess-propeller, it is not easy to do this by winding 
the propeller itself. 

Oil the bearings well before you wind up the 
rubber ; the part beyond the screw eye will not coil 
as the other “ free ” length does, but it should lengthen 
the duration of running. 








HOW TO MAKE A MODEL CAR DRIVEN 
BY AN AERIAL PROPELLER 


I T is quite possible to drive a car by means of an 
aerial propeller, and, as most boys are interested 
in anything novel, I propose to give instructions for 
making a model rubber-driven “ aerial ” car. 

One of my diagrams is to scale, therefore you can 
measure up any part of the model. About 20 in. 
is a good length for the car alone, but provided you 
keep roughly to the proportions given, the exact 
size does not matter very much. Sketch 1, Sketch 
Plan, will give you a good idea of the method of 
building up the body of the car ; the wooden parts 
are grained, but those left white are composed of 
tin. Use stout black pins to fasten the tin to the 
wooden ends, bore the holes in the metal with a 
small awl just large enough to receive the pins. 

The fixing of the long arm which carries the pro¬ 
peller and the rubber motor is quite simple; the 
uprights are screwed to the front and back of the 
car, and the top batten is screwed to the uprights 
(see Sketches 1 and 2, Scale Plan, and Sketches 1, 5 
and 7, Sketch Plan). Sketch 6, Sketch Plan, will 
give a good idea of the mode of joining the tin and 
the end pieces to the baseboard. 

Use disc-wheels, for they are easy to fit; wooden 
wheels of this kind can be bought at toy-shops. 
You can either draw a circle round the top of each 
disc and paint that part to look like tyres, or fasten 
some rubber bands round your wheels with tyre 

205 


206 


Something to Make 


solution. 
Make two 
wooden axles, 
as shown on 
Sketch 2, 
Sketch Plan, 
screw your 
wheels to the 
axle, but re¬ 
member they 
must revolve 
freely upon 
the screws , which should be quite thin. The axle a 
must be fastened to the baseboard by means of the 
screws shown, s. 

Build your car lightly, but, as the extreme light¬ 
ness which is necessary in constructing a model aero¬ 
plane need not be aimed at, you may use tin for your 
propeller. I have devised a new and simple way of 
making this important fitting (see Sketch 2, Scale 
Plan, and 3 and 4, Sketch Plan). Sketch 3 shows 
the propeller flat—before the blades are bent, b is 
a wooden block and must be screwed to the tin (see 
side view, Sketch 4). The shaft is merely a piece 
of brass or mild steel wire, on to which, before bending 
the hook , a small coil of brass, zinc, or aluminium 
(sec Sketch 8), or a tiny nut must be fitted to keep 
the propeller from touching the bearing. Note care¬ 
fully how the front of the shaft is turned back like 
a staple and clinched into the wooden block b . Bend 
the blades as shown on Sketch 2, Scale Plan—you 
need not do this until the propeller is fixed in its 
place. 



Sketch Plan 


































Simple Model Making 207 


The bear- 
ing (see 
Sketch 5) is 
simply a piece 
of rather thin 
brass or gal¬ 
vanized iron, 
screwed to 
the batten as 
shown. The 
metal must be 
thick enough 
to stand the pull of the rubber without bending. Keep 
the propeller shaft long as shown on Sketch 4, but 
if it wobbles—it should not do so if properly fitted— 
use a double bearing. A 10-in. propeller should 
give good results, but you can experiment with 
different sizes if you like. For your 44 engine ” use 
four loops—six if necessary—of good aeroplane rub¬ 
ber, which can be bought at about a penny per foot 
at any rubber shop. Keep the loops quite distinct 
and tie the ends with fine water cord. 

By lengthening the top batten you can use a longer 
piece of elastic, but remember, do not take the pro¬ 
peller any farther out in front of the car or it will 
44 nose-dive ” as it gets up speed. It is for this 
reason, too, that I have made the after support of 
the batten a little lower than the forward one. Take 
your batten out beyond the back of the car as far as 
you like—within reason—but do not overweight 
the front of the model. 

A driver’s seat is shown, but remember the shape 
and fittings of your car are of no great importance. 



Scale Plan 

















































2o8 Something to Make 

The steering-wheel is, of course, a “dummy,” but it 
adds to the appearance of the car, and you can easily 
make it out of one of those tin wheels which are 
fitted to cheap toys. 

The important part of your machine is, of course, 
the propeller, the bearing and the rubber e. Bend 
the blades of the propeller exactly as shown on the 
sketch ; a great deal depends on getting the proper 
curve. Then see that the shaft works easily and that 
the little coil upon it is loosely fitted; wonderful 
results can be obtained with rubber motors, if you 
make them properly. 

Now, about painting the car. You will notice 
that I have shown dark bands on the forward part 
of the model, but you can, of course, please yourself 
as to your colour scheme. Red bands painted upon 
a white ground would look well, but some lads seem 
to like “ all grey ” models. One or two small tins 
of art enamel, sold at about twopence each, are just 
the things for painting models, but use soft camel- 
hair brushes, and remember that enamel must be 
slightly thinned out with spirits of turpentine. 

You may wind up your rubber until black balls 
form all along the loops, and it is well to remember 
that a few strands of elastic give a slow T moving pro¬ 
peller but lengthen the duration of running, whereas 
a large number of loops give great power but your 
screw will soon “ play itself out.” Do not try for 
extreme power, the best results are obtained with 
four or five strands (not loops) of rubber. 

Oil frequently, with good cycle oil, the bearings 
and the screws upon which the wheels turn. Some 
soak rubber motors with water. 






HOW TO MAKE A MODEL TUBE 

RAILWAY 


T3EF0RE you commence to build your tubes and 
rolling stock, it is as well to make out a rough 
plan of your line. Do not dig up the lawn, for ex¬ 
ample, nor damage the potato patch, or there may 
be trouble. No doubt you will be able to find an 
odd piece of ground in some corner of your garden, 
but do not make too long a line at first. 

Tin is, of course, the best material to use for 
your tubes, but at a push, cardboard, well painted , 
will answer very well. I think, however, you may 
be able to obtain some odd pieces of metal; for 
example, old tin showcards, or sweet tins, can some¬ 
times be obtained from tradesmen. I have pur¬ 
posely not drawn the tube to scale, for the exact 
height of your little tunnel must depend upon the 
size of the train. I suggest that for the motor you 
use clockwork taken from a cheap model engine 
(obtainable at any toy shop) ; it would be advisable 
to buy as small a one as possible. All things con¬ 
sidered, I should not exceed five inches for the height 
of the tube. 

Sketch 3, Sketch Plan, clearly explains the mode 
of making a tube—either of tin or cardboard. The 
base is just a piece of thin board to which the tin (or 
cardboard) is to be tacked with fine brads. The 
mode of fastening two or more tubes together is given 
on Sketch 1, Sketch Plan, and a little rivet is shown 
on Sketch 2. By the way, a couple of dozen paper- 
H 209 


2io Something to Make 

fasteners would make splendid rivets, but get small 
ones, and hammer the pointed ends down well. 

You must have “ metals 55 inside the tube, or 
your train will soon stop, and, if pocket-money is 
plentiful, by all means get a few lengths of those 
splendid little lines made by Messrs. Gamage and 
other metal dealers. These tracks are sold so cheaply 
that it would save a lot of trouble if you ordered a 
few lengths, but, if the state of the “ funds ” will 
not permit you to do so, see if you can make a wooden 
line as shown on Sketch 5, Sketch Plan, using long 
straight battens screwed to the baseboard of your 
tube. Remember you must buy the wheels for 
your train first of all, so as to know the width of the 
line. We will return to the making of the train 
presently. 

Having made as many lengths of tube as you need, 
dig out a trench in which to bury them. You must 
leave the ends open ; that is to say, little pits must 
be dug so that you can see what is going on at the 
stations, which it will be well to place at the ends of 
the line. A larger tube is joined to the main line to 
contain the platform (see Sketches 8 and 9, Sketch 
Plan). Cover as much of the station tubes as pos¬ 
sible with earth, but, as I said just now, some part 
of the ends must be left uncovered or you cannot 
see the train, nor could you work the line without 
openings at both ends. On Sketch 9 you will see 
that a part of the tube has been cut away on one 
side ; it would be a good plan to leave only this part 
and the end uncovered. 

A station-house and a lift can be made quite 
easily. The house might be of wood, wood and tin, 






Simple Model Making 211 



or cardboard painted with two coatings of good oil 
paint. Black pins are just the thing for fastening 
the house. The lift is simply another tube placed 
vertically, and the way in which you can make the 
two cars of tin or wood is shown on Sketches 6 
and 7. Two rollers, on little tin frames, made as 
shown on Sketch 4, Sketch Plan, should be placed at 
the top of the lift, and the cars can be made to ascend 
and descend by cutting little doors where the dotted 
lines come on Sketch 6, and then ballasting the car 
which is to descend. A tiny scrap of lead placed in¬ 
side one car will, of course, cause it to drop quickly, 
bringing up the empty car. By reversing this pro¬ 
cess the other can then be made to drop. 

Now' about that train or trailing coach. I take 
it that you have bought a cheap clockwork engine 
and tender. Carefully remove the boiler and funnel, 
leaving only the clockwork and the w r heels (see Sketch 
8, Scale Plan). Now put this motor on one side, 















































212 Something to Make 

and proceed to make the body of your train or 
car. 

As the wheels of the tender are to be used for 
the “ bogie ” at the back of your coach or car, take 
them out of their bearings (most likely two wheels 
are fastened to one axle) and slip them into the bear¬ 
ings shown on Sketch 2—these you must make at 
the rear of the model. This simple way of fitting 
wheels has been used by model makers for years 
past. Now make the body of the coach of tin ( t , 
Sketch 1), bent round and fastened to a wooden 
base and wooden end-pieces, as shown on Sketch 1 
and Sketch 4, Scale Plan. Please note very care¬ 
fully that the clockwork motor is to be fastened to 
the forward end of the coach (inside), as shown on 
Sketch 5 (dotted lines). Bore holes through the 
frame of what was—before you removed the boiler— 
the engine, and screw it in position under the base¬ 
board of the coach, taking the screws upwards, as 
shown on Sketch 3, Scale Plan. The four wheels 
taken from the tender can be made to slip into the 
rear end of your tin body, as shown on Sketch 2. 

The ventilators on the top of the coach can be 
represented by a long batten, cut as shown on Sketch 
6, Scale Plan, and screwed to the top of the model ; 
paint in the (supposed) openings, as shown on 
Sketch 7. 

The rear gangway can easily be made with some 
slips of tin and a little wire, but the front of the car 
should be of wood, shaped and fitted as shown on 
Sketch 5, Scale Plan. Glass windows could be fitted 
to the coach—train, some call it—but it would be a 
troublesome job, and I should just carefully paint 





Simple Model Making 213 

the windows, etc., on the tin. Art enamel in 
small tins (sold at about twopence each), well diluted 
with turpentine, is the best paint for this model. 
If that part sketched in black were coloured dark 
red, the tin round the windows white, and the roof 
grey, the effect should be good. When I say well 
dilute the enamel, I do not mean make it sloppy 
with turpentine. Enamel must always be diluted 
until it flows well, for if it is put on to a model just 
as it comes from the tin, a week or more may elapse 
before it dries thoroughly. 

There are one or two questions which no doubt 
you would like to ask ; I will try to anticipate them. 
44 If I make the tube in short lengths, how am I to 
join up the metals ? ” you say to yourself. Well, 
there are several ways of doing this. You might 
fasten up two sections at a time, carrying the 
44 metals ” through them and fixing the track to the 
baseboard as you go on. As I take it that you will 
make a straight railway, there is no reason why the 












































































214 Something to Make 

baseboard should not be continuous—not neces¬ 
sarily in one piece—but the tin tube which you build 
over it could be in sections. 

You also wish to ask, no doubt, how deep you 
should bury the tube. Do not go too deep, or you 
will have trouble over the working of the train. If 
you like, the line might run out into the daylight at 
one or both ends. The train, or coach, could start 
in the open, and then run into the tube. Again, 
you might have only one station, right in the middle 
of the line, but, as you would have to let all trains 
“ run through ” this station, I fear that the passen¬ 
gers—if you get any—may complain. 

See that you leave an opening in the side of the 
coach for winding up the clockwork. Just a small, 
round hole, bored in the tin, will allow the key to be 
fixed to the motor. Many of the modern clockwork 
trains have fixed keys : in that case make a small 
door in the side of the coach. 





HOW TO MAKE A MODEL OF 
“SHAMROCK IV” 

A LL the model yachts seem to be “ Shamrocks ” 
in these days, but few of them resemble Sir 
Thomas Lipton’s famous cutter. However, in this 
chapter I will explain how you can make a boat that 
will resemble the America Cup challenger very 
closely. In order to be exact we will build to a 
quarter of an inch to the foot scale, therefore, as the 
Shamrock is 110 ft. long over all, a 27 \ or 28 in. 
model will be just the thing and a very nice size to 
make. 

Do not buy a block of wood, but build your boat 
in two halves (see Sketch 1, scale plan). By so 
doing you can hollow out your model very easily, 
and two small blocks will be cheaper than one big 
one. Shamrock is 23 ft. wide, but it will be advis¬ 
able to make the model 6 in. wide, to allow for the 
difference in size. Allowances of this kind must be 
made, because everything about a model is relatively 
heavier than it would be upon a full-sized craft. 

Forget all about the fin (f, Sketch 1) whilst you are 
cutting out your hull. The two blocks should be 
about three inches square , and, of course, 28 in. long. 
You might easily cut out your boat with a big pocket- 
knife and a lot of the inside could be carved away, 
but a good gouge and a small plane will be useful. 
Refer to Sketches 5 and 7 (scale plan) for the shape. 
Remember you need not trouble about the fin yet. 

See that you make both sides of your boat true, 

215 


216 Something to Make 

for a lop-sided model will simply go round and round. 
You then can test the sides by making cardboard 
moulds and placing them alongside the hull as you 
work. Also be very careful that you do not cut two 
right sides in place of a right and a left side; it is easy 
to make this mistake when building your boat in 
two halves. 

When you have cut both sides to your satisfaction, 
smooth the wood by rubbing it down with three dif¬ 
ferent grades of glass-paper, starting with the roughest 
and working down to F (fine). A spokeshave is use¬ 
ful for cutting the outside of the boat, and a small 
iron plane should be used for the final stages. Cut 
away as much of the inside as you can with a knife, 
then use a small gouge, but take great care not to 
go through the sides. Remember the more you take 
out of your boat the better she will go. 

It is not altogether easy to join the two halves of 
the model, although most people would say it was 
“ as easy as winking.” The bow (front) will be thick 
enough to take a fine screw, and you could join the 
stern by screwing a thin piece of tin or wood to the 
part left white on Sketch 5 (scale plan). You will 
find that the middle of the boat must be fastened 
quite securely, but anything screwed outside the hull 
looks very unsightly. Now glance at Sketch 4 
(scale plan) and you will see how small pieces of tin 
can be screwed inside the hull to hold the halves to¬ 
gether. Before you fasten them, however, you must 
make the fin f. 

On Sketch 7 (scale plan) I have grained the fin, 
so that you may see that it is to be made of wood. 
Any nice piece of board will do, but it must not be 





Simple Model Making 217 



“ splitty.” The best way to go to work is to get a 
piece of wood 12 in. long and about three-eighths of an 
inch thick, then you can cut and taper this as shown 
on Sketch 5 (scale plan). Do not make your fin 
any thicker than is absolutely necessary, but, as 
you will have to drive screws through the lead up¬ 
ward into the wood, it must be thick enough to take 
a long thin screw without splitting . Remember that 
the fin must be exactly in the middle of the boat, 
therefore you must slightly notch both the halves 
of the hull where they touch the fin. Thus, 
when the two pieces are joined, there will be a slot 
into which the fin will fit, but it must be fastened 
securely. A good way of fastening the fin is shown 
on Sketch 2 (scale plan), t is one of the cross-pieces 
made of tin (this is also shown enlarged, Sketch 3). 
You will see how these cross-pieces are screwed to the 


























































218 Something to Make 

sides of the boat and to the top of the fin, but as the 
bottom will be very thin take long fine screws upward 
slantwise into the fin, as shown at s, Sketch 2 (on 
the right of k ). 

A nice piece of fretwork wood is the best thing 
to get for the deck—fasten it on the top of the hull 
(do not “ let it in ”), using stout black pins as shown 
at 13 (sketch plan). Complete the inside of the boat 
before putting the deck on ; a coating of boiled oil 
inside will prevent the water from soaking into the 
wood. Be sure also to make a “ step ” for the mast 
before you put the deck on (see Sketch 12, sketch 
plan). As wood splits use a small piece of sheet lead 
for the “ step,” and screw it to the bottom of the 
boat exactly in the centre of the two hulls—the mast 
should be “ stepped ” 9| in. from the bow, or front 
of the boat. Roughly tack the deck in place before 
finally fastening it, in order that you may see if the 
mast fits into the “ step ” so that it is upright. If 
it does not do so take the deck off again. Do not 
fasten it all round and then find that you have got 
things “ all adrift.” 

For mast and spars I should advise you to use 
bamboo, but do not get thick bamboo. What the 
shopkeepers call “ garden canes ”—they are sold at 
a penny each—are what you require, but you may 
find that a slightly thicker cane is needed for the 
mast. I want to impress upon you, however, that 
half the boys’ boats fail because their masts and 
spars are too thick and heavy. Bamboo is so strong 
that even a thin cane will stand—well, “ almost any¬ 
thing,” and no shrouds (ropes to support the mast) 
are needed. Sketch 11 shows a mode of interlocking 






Simple Model Making 


219 


two screw eyes by opening 
the eye of one and then 
hammering it up again after 
joining the pair. One eye 
is screwed into the mast, 
and the other into the end 
of the boom ; this should 
be done before they are 
interlocked. Cut little 
“ jaws ” out of zinc, brass 
or aluminium (see Sketch 
9, sketch plan), and fasten 
them to the gaff by means 
of pins driven through the 

bamboo—coil the pointed 3cA>.e feet _ 

ends—using small round¬ 
nosed pliers. The sheets (the cords which loosen or 
tighten the sails) are shown on Sketches 10 and 11 ; 
10 is the “jib sheet,” and 11 the “ boom ” with its 
sheet (b is the boom and g the gaff). 

So that you can loosen or tighten your sails little 
“ bowsers,” or “ blocks,” must be made ( see Sketch 
4, sketch plan). Do not be frightened : any small 
oblong piece of zinc, bone, or aluminium bored twice 
will do, and if water cord is threaded (as shown at 4) 
into your “ pulleys ” they should hold well and stay 
where they are placed. 

The sails are t, the topsail ; m, the mainsail ; j, 
the jib ; and f, the foresail. These should be made 
of some strong light fabric—not muslin, as that 
material is too flimsy. Special sailcloth can be 
bought, but it is rather dear; any light closely 
woven material will do almost as well as the prepared 















220 


Something to Make 


sailcloth, however. The “ selvedge ”—the woven 
edge which does not need hemming—should always 
be placed along the after side of each sail. Get your 
sister to hem your sails, but be very careful to cut 
them properly. Place the material on a table or 
clean board, pin it down, then rule off your sails 
with a pencil, taking care to allow for the hems. 
You will notice that eyelets are placed along the 
forward edges, so that the sails can be laced to the 
mast, or, in the case of the headsails, threaded (see 
Sketch 10, sketch plan). Small boot eyelets can be 
bought very cheaply, and I generally hammer them 
flat, after inserting them in the material, by means 
of a door key and a light hammer. 

Making the rudder is rather a tricky job, but it 
is possible to cut a rudder out of one piece of zinc or 
thin galvanized iron. Look at Sketch 6 (scale plan) 
and you will see how to cut and commence to coil 
the stem. Now keep hammering c until it coils up 
closely. The top of the stem may be slightly flat¬ 
tened, but take care that it slips easily through 8 
(sketch plan)—the rudder tube made of brass— 
which must be taken through the boat at f, Sketch 1 
(scale plan). Please note the way in which the 
lower end of the tube is to be cut, so that it can be 
bored and screwed to the deadwood f. Bore two 
small holes at top of the rudder stem to fasten the 
wooden tiller (see Sketch 7). Note that three screw 
eyes are shown placed at equal distances along the 
tiller ; there is also a cord and rubber band at the 
end. When sailing fasten the rubber band to the 
stern of your boat so that it is stretched fairly tight. 
If the band is quit ' central your rudder will be held 









Simple Model Making 221 

amidships, will 
it not ? Now 
if you hook 
vour mainsail 
cord — the 
“ main sheet ” 
we call it—to 
one of the tiller 
eyes, I need 
not tell you 
that as the sail 
pulls, the 
rudder will be 
“put over” 
slightly. B y 
using the outer 
eye you can 
get a lot of 
leverage, or, by trying the inner one, very little. 
Thus it is possible to make the boat steer herself. 

Get a plumber to melt your lead keel if you can. 
Some boys manage this job fairly well, but it is pos¬ 
sible to burn yourself badly. A kind of rough box 
is made, into which the lead is poured (see Sketch 3, 
sketch plan). The wooden plugs shown on the 
sketch will make the holes for the screws ; the char¬ 
red wood can easily be bored out of the lead. Remem¬ 
ber that the mould must be well puttied outside, but 
the inside must be kept quite dry, or you may have 
an explosion and the lead flying up in your face. 
Lead can be carved when cold like wood ; use a plane 
or a spokeshave. 

Well stop all cracks in your boat with putty, 








































222 Something to Make 

smooth her off, give her a coat of priming and at 
least two coats of paint, taking care to rub down 
the surface after the first coating. The deck should 
have two coatings of good hard varnish. 

Sketch 2 (scale plan) shows the screw-eyes placed 
to hold the bowsprit—“ the stick which sticks out 
in front,” as I heard a boy call it lately. Sketch 5 
shows the gaff and fittings, and Sketch 14 a simple 
hook that will not come unfastened. 

May you have luck with your “ Shramrock,” and 
lift the America Cup—or any little cup you club 
together and buy. 






HOW TO MAKE A MODEL 
SEARCHLIGHT 


3 


T HE miniature searchlight shown in Fig. 1 can 
be made with any lens about If in. or 2 in. 
in diameter and not more than 3 in. focus, either 
bi-convex (that is, having both sides curving out¬ 
wards) or plano-convex (having one side flat and one 
curved). 

To find the back focus, take a white card, point 
the curved side of the lens towards an object at least 
a hundred yards away, such as a chimney or spire, 
and move the card to and fro behind the lens until 
a perfectly sharp inverted image of the object is 
thrown on it. Then measure from the back of the 
lens to the card. This gives the distance at which 
the lamp must be fixed. 

We want a tube about If in. longer than the 
focus of the lens, and the same diameter as the latter 
inside. One may be made in tin by those who can 
solder, or a piece can be cut from a cardboard postal 
tube by scoring round with a sharp knife. 

The following materials and accessories are also 
needed : A miniature screw lamp-holder with china 
base (Fig. 2), a 4-volt flash-lamp bulb (Fig. 3), a 
yard of twin flexible, silk-covered copper bell wire, 
a 4-volt flash-lamp battery, some strip brass in. 
thick, and a few small brass screws. All these may 
be obtained from an electrical supply store. 

Cut a wooden disc (Fig. 4) about f in. thick, to 
fit closely inside the tube, and in the middle of this 

223 


224 Something to Make 

screw the lamp-holder. Bore two holes at a and b 
for the wires. 

Obtain or make a wooden box about 5 in. by 
4 in. inside, and 1 in. deep, to hold the battery. It 
should have a flat lid. 

Cut a block of wood 2 in. square and trim it to 
the conical shape shown in Fig. 5, so that it is 2 in. 
high, lj in. diameter at the bottom, and § in. 
diameter at the top. Fix this outside on the loose 
top of the box by a couple of screws from 
underneath. 

Bend a piece of the strip brass as in Fig. 6 to form 
the cradle, drilling or punching a small hole near 
each end and a larger one in the middle. Screw 
the cradle on the top of the conical pedestal, so as 
to be just loose enough to turn round. 

Bend a short strip of brass as at A in Fig. 7, and 
cut another piece as at b. Make a hole in each as 
shown, and secure them by brass screws to the top 

of the box, to form 
the spring switch. 
Bore two holes in the 
top for the wires, 
by the side of either 
piece, as seen in Fig. 1. 

Bend a cardboard 
ring to fit closely in 
the tube, and glue it 
at the front, as seen 
in section at a in 
Fig. 8. Clean and in¬ 
sert the lens, curved 
side outwards, secur¬ 



ing. l 
























Simple Model Making 


225 



Fig. 5 Fig. 6 Fig. 9 


ing it by gluing in a second ring b. Pierce two small 
holes at each side of the tube, diametrically opposite, 
so that it may swing truly, apply glue under the 
heads of two drawing-pins and pass the points through 
the holes from inside so that they project, pressing 
the glued heads into contact with the tube. It is 
as well to blunt the points first with a file. When 
set, fit them into the cradle. 

Untwist the two strands of wire, which is to be 
used single. Cut two pieces 6 in. long and one piece 
8 in. long, and with a knife scrape off about 1J in. of 
the covering from the six ends, exposing the bare 
copper. Loosen a terminal screw on the holder 
(a or b, in Fig. 2), twist the bared end of the 6-in. 
piece tightly round it near the top, and reinsert the 
screw. Similarly attach the 8-in. piece to the second 
terminal screw, carrying the wires respectively 
through the two holes in the wooden disc. Screw 
the lamp into the holder and temporarily fit the 
disc into end of tube. 


o 



























226 Something to Make 

Attach the end of the short wire to the screw on 
the bent brass strip, as seen in Fig. 1. Pass the 
longer one through the hole in the top nearest the 
pedestal, and twist the end tightly round one of the 
brass battery terminals, as indicated in Fig. 9. Take 
the third wire, twist one end round the second bat¬ 
tery terminal, pass the other end through the top, 
and attach it to the screw on the flat brass strip. 
Cut off any loose ends of bare wire. 

If all has been done correctly, the lamp will now 
light up on pressing the bent brass strip into con¬ 
tact with the flat one, and is instantly switched off 
when the bent strip is released. (By an artistic licence, 
the searchlight is shown working without the switch 
being pressed.) See that the beam is properly 
parallel, and, if not, shift the wooden disc slightly, 
then glue it in at the ascertained position. Lastly, 
put the battery in the box and nail or screw the 
lid on. The tube and box (but not the brass parts) 
may be given a coat of iron-grey paint. 






Section IV. 

MISCELLANEOUS THINGS TO MAKE 


HOW TO MAKE A TELESCOPE 

I T is quite possible to obtain lenses for making 
telescopes at a moderate figure. It is advisable 
that I should mention this, because writers frequently 
tell their readers to make instruments or models 
the materials for which would cost a large sum. 
One should remember also that few lads own lathes, 
and that to ask them to make brass tubes and lens 
fittings is to set them a task which they cannot 
accomplish. In this article it will be my endeavour 
to suggest simple devices by which these difficulties 
can be overcome. 

To begin with I suggest that, first of all, you 
make a very simple telescope; then, if you feel 
inclined to construct a bigger and better one, you 
have Sketch 3, Diagram 1, to guide you. 

Before you commence work, get the lenses and 
find the focal length of the object-glass (o, Sketch 1, 
Diagram 1). If the focal length of the lens you wish 
to use is unknown, it can be found by holding the 
glass up before a piece of white paper pinned to, 
say, the wall. If you measure the distance between 
the lens and the paper when the image of whatever 
scene is before the glass comes up “ sharp,” you 
have the focal length for working purposes. 

Now, as some of my readers may wish, just as 
an experiment, to begin with lenses which they 
have in hand, I have made one or two experiments 

227 


228 Something to Make 

with odd glasses which I have had thrown aside 
for years. I took a 3-inch reading glass—rather 
a poor lens by the way—and a small eye-piece 
which once belonged to a pair of opera-glasses. This 
I roughly fitted into a paper tube and held in front 
of the reading glass ( see Sketch 1, Diagram 1). 
Even with these makeshift materials I was able 
to read the name of a street, posted up at some 
distance from my house. The opera-glass eye-piece 
gave an upright image—not inverted as would have 
been the case had I used, say, a small, ordinary 
magnifying glass for an eye-piece. 

Now to begin with I advise you to make a tele¬ 
scope on the lines of the one shown on Sketch 2, 
Diagram 1. I wish to point out that although the 
instrument depicted on Sketch 3 is to scale, I have 
purposely avoided making Sketch 2 to any scale. 
As probably you will wish to begin by making the 
simple telescope, it is as well to leave the measure¬ 
ments as open as possible, for the size of your instru¬ 
ment will , of course , depend upon the focal length of 
your object-glass. If I give a fixed size you may 
perhaps miss a bargain in the way of a second-hand 
glass. Firms like Messrs. Dollond, of Oxford Street, 
W., or Messrs. Gamage, of Holborn, will supply 
you with almost any kind of lens, but my advice 
is that you make this experimental instrument with 
any glasses you can obtain or have in hand which 
seem suitable, then, if you decide to make a better 
telescope on the lines of Sketch 3, for example, get 
the whole of the lenses from one firm. 

Having obtained a suitable object-glass, and 
either the eye-piece from a fie d or opera-glass or 





Miscellaneous Things to Make 229 



Diagram 1 


a double concave lens such as those used in the 
Galilean telescopes, you may commence work. 

If you buy brass tubes you will have to pay, 
probably, a big price, and I do not altogether like 
the idea of pasteboard tubes which are sometimes 
used by amateurs. Possibly some of you know 
what splendid stuff sheet aluminium is to work with 

_why not use this material ? For the block at 

the end of the tube a wooden ring of great thickness 
would be very suitable, but there is this objection 

_few of my readers have tools for making such a 

ring. On the whole I think the best kind of block 
will be one made up in the same manner as paper 
model yachts are constructed, namely, of paper 
bound together with a mixture of methylated spirit 
and shellac, which dries quickly and is perfectly 
watertight. 







































230 Something to Make 

Aluminium is getting cheaper, and, as the amount 
you will require will be but a few square feet, you 
should get it cheaply at any good ironmonger’s. 
Aluminium having a percentage of tin or other 
metal mixed with it is better than pure aluminium. 
I used this stuff (about the thickness of stout note- 
paper) for making a model yacht, and it proved 
quite satisfactory. By the way, you might join 
your tube in the same manner that I did my boat, 
namely, by screwing the edges to a thin wooden 
backing with tiny brass screws (the smallest size 
you can obtain). Sketches 1 and 2, Diagram 2, 
will show you clearly how this is to be done, but, 
in order that the sheet aluminium shall be bent 
into a perfect cylinder, it should be placed round a 
roller of exactly the size as you wish your tube to 
be when finished. Although, on Sketch 2, the 
wood backing is shown reaching right to the end 
of the tube, some of it will have to be cut away 
before the ring (Sketch 5) is inserted. 

On Sketch 2, Diagram 1, you see an achromatic 
object-glass o, fitted to the tube ; R being a ring 
of wood, or paper, cemented to the tube. On Sketch 
8, Diagram 2, an ordinary lens l is shown ; b being 
the blocking ring stuck to the tube, and r a metal 
ring (see Sketch 3), which can be slipped in in front 
of the lens to keep it firmly in its place. A piece 
of steel wire, carefully bent round as shown on 
Sketch 3, Diagram 2, will do nicely for this useful 
fitting. 

The mode of making the blocking rings of paper 
is shown on Sketches 4 and 5, Diagram 2. Brown 
paper is usually preferred for making paper models, 







Miscellaneous Things to Make 231 

and in order to get a perfect ring this will have to 
be wound round a wooden roller of suitable size. 
Do not stick the paper to the roller , wind a coil or two 
round the wood before you apply the shellac. Buy 
half a pint of methylated spirit, and an ounce or 
two of shellac, which must be put into a deep jar 
and covered with the spirit, then leave it to dissolve 
for a few hours. Probably you will then find that 
the mixture is about the consistency of cream? 
and it can be diluted with more spirit if too thick, 
but do not thin it out too much. Cut long strips 
of paper exactly the width you wish your ring to 
be, give them a thick coating of the mixture, and 
coil them round the roller until the required thickness 
is obtained. On account of the many coils the ring 
should be left upon the roller for some time—until 
it is quite dry, remember. It might be advisable 



Diagram J 2 


































232 Something to Make 

to grease the roller well before placing the paper 
upon it, for if shellac once sticks to wood it is “a 
case.” 

Any good cement or Mendit might be used for 
sticking the rings to the tube, but do not glue the 
object glass to the tube, the steel ring e will hold 
it firmly ; remember you may wish to remove the 
glass occasionally. The smaller tube for the eye¬ 
piece e, Diagram 1, can be made in the same way 
as the big one, if not too small. Should you decide 
upon a very tiny instrument probably it might be 
advisable to overlap and rivet the small tube, or 
to make it of pasteboard on a roller as you did the 
rings. I should glue or cement the eye-piece into 
the end of this tube ; to clean it, thrust a silk hand¬ 
kerchief or something very soft down the tube 
with a stick. 

It is vital that the glasses should be quite squarely 
fixed in the tubes, they must on no account be 
placed in a slanting position. 

Where the edge of the tube projects beyond 
the object glass (see 2, Diagram 1), I should advise 
you to fit a ring, or two rings, of aluminium, so as 
to thicken the tube at this point. Really these 
extra rings should be riveted in place—it is difficult 
if not impossible to solder aluminium—but, if you 
cannot get suitable little rivets, try cementing the 
rings. Of course these rings are not absolutely 
necessary, but at the end of the tube the sharp 
edge of the metal might get bent. Aluminium is 
so soft that after the rings are in position the edges 
may be nicely rounded by rubbing them with glass- 
paper. 






Miscellaneous Th ings to Make 233 

Now, if you have made a success of your first 
telescope, you may wish to construct the larger 
one shown on Sketch 3, Diagram 1. The general 
method of construction will be similar to that of 
the smaller instrument, except in connexion with 
the eye-piece tube, of which more presently. 

You will note that I have drawn Sketch 3 to 
scale. The dimensions of this instrument are those 
of a fine 3-draw telescope which I have in my pos¬ 
session, except that to simplify the construction 
I have done away with two of the draw-tubes, 
making a long main body. The construction of 
this body will be exactly the same as that shown 
on Sketch 2. The object-glass is lj in. in dia¬ 
meter. The chief alteration is in the eye-piece 
tube, which has an erector (see er) consisting of two 
lenses and an eye-piece, also consisting of two 
lenses (see also Sketch 7, Diagram 2). Note 
that the small lenses are enclosed in separate tubes 
(see a and b, Sketch 7). You can please yourself 
whether you attempt to make the outer tube or 
buy one ready made; I suggest that you buy one, 
but I do not propose to ask you to make the smaller 
tubes (for the erector and the eye-piece). I consider 
that it would be too delicate a job for the average 
reader. If you can do so it would be as well to 
buy ready made the whole of tube a (Sketch 3, 
Diagram 1). 

It is not absolutely necessary that you keep to 
the lj in. object-glass, but get the whole set of 
lenses from one optician; he will, of course, if you 
request him to do so, see that you get them in suit¬ 
able combination. By all means get the lenses 








234 Something to Make 

before you begin to make the tubes, for if they are 
not those shown on my scale plan (only 3, Diagram 1, 
is to scale) they will, of course, require different 
sized tubes. 

I think now you see the general mode of con¬ 
struction. I need hardly add that the eye-piece tube 
is to slide freely in block b (Diagram 1). This is, 
of course, for focusing. 

As long as you grasp the general mode of con¬ 
struction it does not matter if you modify things 
to please yourself, or so that you may fit in any 
material you wish to use. Some people advise 
pasteboard tubes, I believe, and for the big tube 
there is no reason why you should not make this 
kind if you wish to do so. Whether a draw-tube 
of pasteboard, built up as we did the paper rings, 
would be a success, I doubt, for even if you covered * 
it with aluminium paint or enamel, it would be sure 
to rub off. 







HOW TO MAKE A MICROSCOPE 


TV/TAN\ boys love to study the minute things 
which exist all around us, and even a reading 
glass is useful when examining a flower or a tiny 
insect. As no doubt you are aware, the high- 
powered microscope opens up a world which is as 
new to the average man as America was to Colum¬ 
bus; but such an instrument costs a lot of money, 
and great skill is needed to make it. I do not suggest, 
therefore, that you make a microscope of high power, 
but an instrument with a combination of lenses 
which will give a fair amount of magnification is 
not very difficult to construct. 

The great difficulty in these days is to obtain 
suitable lenses, and, in order to help you in this 
respect, I have been testing a number which I have 
in hand belonging to telescopes, cameras, and simple 
things such as my readers are likely to possess; 
and I found two combinations which will make up 
into microscopes of fair power. For the first of 
these instruments, that shown on Sketch 3, Diagram 
1, you could no doubt obtain suitable lenses of any 
really good optician; but one big firm told me that 
they would have difficulty in supplying lenses for 
high-powered microscopes. As we do not require 
this type of lens, however, we can proceed. Ob¬ 
viously if I suggest a plan by which you can use 
telescope lenses in turn for a microscope, I shall be 
helping you in these days of enforced economy, 
and on Sketch 4, Diagram 1, you will see a combination 

235 


236 Something to Make 

which, although, of course, it does not equal a 
student’s microscope, gives a good magnification. 
Of this more anon. 

After due consideration it seems to me that you 
should make an instrument on the lines of Sketch 2, 
Diagram 1, and, if you have already constructed 
the telescope described in the chapter on “ How to 
Make a Telescope,” you will wish, I am sure, to use 
aluminium as freely as possible. In this case, how¬ 
ever, it will be by no means easy to make up the 
main tube as you did the telescope tube, therefore 
I suggest that you buy some brass tubing at an 
ironmonger’s—ordinary brass tubing will do nicely. 
The diameter will depend upon the size of the lenses 
you decide to use. 

First of all obtain and thoroughly test your 
lenses, but upon this important subject I must 
speak at some length, or you may labour in vain. 
Sketch 1 shows a simple form of microscope, such as 
one frequently sees illustrated in the text-books, 
o is the objective, and e the eye-piece ; naturally 
o gives an enlarged image of anything placed imme¬ 
diately beneath it, and when set at exactly the proper 
distance from o, the eye-picce e presents a still 
further enlarged image to the eye. This is not 
technical language, but I want to make things clear 
to you as quickly as possible. Thus, to get the 
proper adjustment, the eye-piece is placed in a separate 
tube, which slides in the main tube at a. But 
obviously it will be difficult for an amateur to make 
a tapered tube, such as that shown on Sketch 1, 
therefore I have devised the one shown on Sketch 2, 
Diagram 1. 








Miscellaneous Things to Make 237 

We will deal with this type of instrument first, 
then, after describing how to make the fittings » 
which will be the same for either type, I will describe 
Sketch 4. 

Before you decide to buy lenses for the instrument 
shown on Sketch 2, Diagram 1, by all means test 
any you have about, for in this way I found a very 
suitable combination (a big convex lens and a smaller 
one). Do not jump to the conclusion that I wish 
you to place your lenses at exactly the same distance 
from each other as shown on the diagrams. I have 
taken care not to draw the sketches to scale, because 
lenses of different focal lengths will require different 
lengths of tube. In all cases test your lenses by 
placing them at various distances from each other, 
until you get a fine, clear, and much enlarged image 
of the object you wish to magnify. Then carefully 



Diagram 1 
























































































238 Something to Make 

mark off and measure that distance, and make 
your tubes accordingly. If you act otherwise you 
may make your fittings very nicely, only to find 
that your glasses are useless. I have three little 
lenses which give a tremendous amount of magnifica¬ 
tion when placed almost touching each other. 

Make the baseboard first of all—there need be 
no hard and fast limit as to size. If you can get a 
nice piece of mahogany it will look well when varnished, 
but be sure to screw a piece of sheet lead to the 
bottom of this baseboard (see l, Sketch 2, Diagram 1); 
this will keep your instrument from toppling over, 
should you, by mistake, make it top-heavy. The 
upright (shown much enlarged on Sketch 4, Diagram 
2) should also be made of mahogany and the tray 
for the slides s and the block (see 5, Diagram 2) 
should be of the same wood. Please note, on sketches 
4 and 5, Diagram 2, the angle-irons supporting 
the block, the arrangement of the screws, and the 
position of the long screw (see 4) which hinges the 
upright to the block. The reason I suggest this 
hinge is in order that you may—if you wish to do 
so—tilt the whole instrument in the direction shown 
by the dotted lines on Sketch 1, Diagram 2. (Small 
bracket-supports, obtainable at any ironmonger’s, 
might do for what I term “ angle irons.”) 

The clasp in which it is intended that the tube 
shall slide is shown on Sketch 2, Diagram 2—it should 
be made of aluminium or brass ; please refer to 
Sketches 2 (Diagram 1) and 1 (Diagram 2). This 
can be adjusted so that the right amount of grip 
upon the tube is obtained, j is the joint, and b 
a bolt with a nut for adjustment. 





Miscellaneous Things to Make 239 



Diagram 2 


The mirror is, of course, for throwing a strong 
light through the microscopic slide. Sketches 1 
and 7, Diagram 2, show how this part of the apparatus 
is to be fitted ; use aluminium or brass for the support, 
with a brass bolt and nut as shown on Sketch 7. 
Before the war little round mirrors of this kind were 
frequently given away to advertise goods : if you 
buy one see that the metal rim is deep enough to 
stand boring without damage to the glass ; two tiny 
“ Model Engineer ” bolts and nuts, obtainable of 
many ironmongers, should hinge the mirror nicely. 
On Sketch 2, Diagram 1, the mirror-fitting is shown 
fastened to the block, but on Sketch 2, Diagram 1, 
it is fitted to the upright—please yourself which 
method you follow. If you wish to tilt the micro¬ 
scope, fit the mirror to the upright. 
























































































240 Something to Make 

The eye-piece tube (see Sketch 3, Diagram 2) is 
to telescope into the main tube. You should obtain 
two tubes which fit each other rather closely, for 
you must focus the image by pushing the eye-piece 
tube in or out. 

Now I should refer to Sketch 4, Diagram 1. 
Here we have a combination of four lenses, and I 
have introduced this set because many of my readers 
may have obtained a telescope similar to the 3-draw 
instrument described (and depicted) in my chapter 
on “ How to Make a Telescope.” In a good tele¬ 
scope of this kind you will find four small lenses 
in the eye-piece section, two of which are larger 
than the rest. Arrange these in a little tube (c 
on the diagram), which must be of the same length 
as those in the telescope ; then place the lens which 
(in the telescope) is nearest to the eye, at o (Sketch 
4, Diagram 1). Now look at e (the eye-piece); for 
this I used the eye-piece of an opera-glass. You 
must experiment to find the distances at which 
these lenses should be placed from each other—I 
found that such a combination gave a well-magnified 
image ; of course, I do not mean to say that I got 
such results as one would from a student’s micro¬ 
scope, but, if you have the lenses all ready at hand, 
the experiment is well worth trying. Probably you 
will not wish to fix your telescope lenses so firmly 
in the tube that they cannot be extracted quickly, 
so I propose that you get some of those broad flat 
cork stoppers which are used for extract of meat 
jars. By carefully boring a hole in the middle of 
the cork and then enlarging it with a round or half- 
round file, or even glasspaper wrapped round a 







Miscellaneous Thin gs to Make 241 

small roller, you can make cork rings like that shown 
on Sketch 6, Diagram 2, into which the lenses can 
easily be fitted. 

For this combination no telescopic top-tube is 
needed, but you will have to focus by slightly loosen¬ 
ing the nut of the clasp (Sketch 2, Diagram 2) so 
that the whole tube may move fairly easily. 

You will note that the clasp can be made to move 
on the upright, but, at ordinary times, it should be 
held firmly in its place by a couple of screws. Of 
course the cork rings will be glued or cemented to the 
main tube; if you give them a coating of aluminium 
paint no one will know that they are composed of 
cork. Wooden or paper rings would do equally 
well, but you would have to get the wood turned, 
and even then the wood is inclined to split. 

Probably you would get the best results from 
two double convex lenses, specially bought to go 
in combination. If you tell the firm to whom you 
send that you want two lenses to make up into such 
a microscope as that depicted on Sketch 1, Diagram 2, 
they would, I think, send you something very suit¬ 
able. 

Every detail of the construction is shown on the 
diagram, and so that you may have something to 
guide you I have included a bird’s-eye view of 
the tube and the baseboard—Sketch 5, Diagram 1* 
Again I wish to impress upon you that the size of 
your apparatus must depend entirely upon the lenses 
used. There are, of course, many forms of micro¬ 
scope, in some of which complicated series of lenses 
take the place of our simple ones. To make any of 
these you would not only have to be an expert, but 

p 







242 Something to Make 

would also need special tools and the appliances of 
a big factory. 

You ought, nevertheless, to get much instruction 
and amusement from an instrument which you can 
make yourself. With three lenses taken from my 
Dollond telescope, placed within perhaps half 
an inch of each other, I have magnified dust until 
it looked like—well, small stones. As this can be 
done with such a makeshift, if you take the trouble 
to experiment with any suitable lenses you come 
across or have about, you may get a combination 
which, when properly fitted and adjusted, will delight 
you. If you buy the lenses, get as simple a combina¬ 
tion as possible. 

Whilst you are making your fittings go to your 
free library and look up pictures of the more com¬ 
plicated microscopes shown in the encyclopaedia. 
It will be interesting to study them and also to note 
how they have been evolved from the simpler types 
—each being designed for a special purpose. As a 
lad I had a “ craze ” for yacht designing, and I 
read up every book on the subject that came my 
way. Thus, by the time that I was sixteen, I knew 
enough about the passage of bodies through water 
to design a really fast-racing model. Why not study 
the microscope in the same way ? 





“HANDS UP” 

(An Exciting Board-game) 

AM going to ask you to imagine yourself in the 
wild west, where a reward is out for the capture 
of a troublesome horse-thief. For the purposes of 
the game, it will unfortunately be necessary for one 
of the players to represent the latter, the opponent 
being the “ sheriff,” who has at his command a 
posse of mounted police. 

The diagram of the board is a simple one to copy, 
but this, of course, will have to be considerably 
enlarged. 

At each of the bottom corners are three small 
squares marked with the sheriff’s star, from which 
the posse start off on their expedition ; near the 
upper edge of the board is “ the border ”—a double 
line—of much interest to the horse-thief as will be 
seen, and beneath it a range of “ inaccessible moun¬ 
tains ”—shaded—through the centre of which runs 
a “ defile.” 

Conspicuous are two “ woods,” in one of which 
the horse-thief, it is supposed, is known to be hiding. 
It is the object of the sheriff’s officers to seek him 
out and capture or kill him before he reaches the 
border. 

How is this delightful (!) programme carried out ? 
Well, first of all cut out twelve squares of cardboard 
each the size of one of the squares on the board. 
Six of these are to form the “ posse ” and should 
bear a star similar to that figured in the illustration 

243 


244 Something to Make 

(d), the seventh is the horse-thief, distinguishable by 
the outline of a spur (a). On the back of the latter 
piece ( b) and also the remaining five pieces (the under¬ 
sides of which are left blank) an outline of a pine- 
tree should be drawn ( c ). 

Having decided which player is to be the horse- 
thief, he places the desperado in question, with 
two of the blank cards, all with the “ tree ” side upper¬ 
most, on the three central squares (circled with black) 
in one of the woods and the three other blank cards, 
similarly, in the other wood. 

Before doing so he should make sure which is 
the horse-thief, without letting his opponent into the 
secret. The sheriff places his six men on the 
six starting squares at the bottom corners of the 
board and throws the dice, moving one of his men 
a corresponding number of squares to pips in the 
cast (sixes do not count for moves). 

The other player does not yet start to use the 
dice, but merely moves one of his cards—either the 
horse-thief or a blank—to an adjacent square within 
the wood. Obviously his opponent does not know 
whether it is the horse-thief or not which has been 
moved, and herein lies the fun, for the first endeavour 
of the posse is to attempt to surround the horse- 
thief (by getting a man on to each of the four corner 
squares of a wood), when the sheriff may demand 
that all pieces within the wood be revealed (the 
bottoms shown), and if the horse-thief be amongst 
them he is considered captured and the game 
won by the sheriff. But, seeing that the latter does 
not even know in which of the two woods the horse- 
thief is hiding and that the player representing the 








V 



Horse-thief (uprerside). b Hcrse-thief (reverse). c Pine Tree (similar to b ). d Member of Posse. 









































































































246 


Something to Make 


horse-thief has the right, at any time when the run¬ 
away is on one of the outermost squares of the 
wood (except the corner ones, which he is not allowed 
to occupy), to commence to throw the dice and move 
the horse-thief out of the wood (the moves being 
taken in similar fashion to those of the posse), to 
thus effect a capture is no easy matter. Moreover, 
should the sheriff succeed in getting one of his 
men on to a corner square of the wood in which the 
horse-thief is actually concealed, the horse-thief, 
in the event of his happening to be on one of 
the eight squares immediately adjacent, has, when 
his turn arrives, the right to “ fire.” This is done by 
casting the dice, and if a six is thrown the 
particular member of the posse is considered 
to be shot and the piece is removed from the 
board. 

Obviously, however, in this case the horse-thief at 
once reveals his position and the remaining members 
of the posse may be hurried to the spot. 

Though it is not essential, even then, that the 
horse-thief should be moved out of the wood, it would 
be wiser to do so, as it would then be a comparatively 
easy matter to surround him (in the manner before 
described). 

Should the player representing the horse-thief 
elect to move his man out of the wood, he throws 
the dice and moves in the ordinary w r ay, either making 
for the shelter of the opposite wood, where he may 
resume his previous tactics, or for the defile in the 
mountains which leads to the border—and to liberty. 
Immediately the horse-thief is moved out into the 
open the piece must be turned “ spur-uppermost.” 






Miscellaneous Things to Make 247 

(The blanks, of course, are never moved by the aid of 
the dice or, in any case, out of the wood.) 

When the horse-thief has revealed himself and 
taken to the open the game resolves itself into a 
chase, during which, should the sheriff get one 
of his men within a distance of three squares of the 
horse-thief (other than diagonally), and it is hia 
turn to throw, he may, in lieu of a move, claim a 
shot by crying “ Hands up,” and then if he throws 
six, the horse-thief (who it is assumed is not 
disposed to submit tamely to capture) is supposed 
to be killed and the sheriff is the winner. Should 
the pursuer, however, be unsuccessful, the horse- 
thief may reply with a shot (similarly by the player 
crying “ Hands up ” and sacrificing a move), and 
should six be scored the pursuer is supposed to 
have fallen a victim to the horse-thief and is removed 
from the board. 

An important rule to remember is that while 
the sheriff’s men can only fire when the horse- 
thief is within three squares directly in front, at the 
rear, or to right or left, the horse-thief has the 
additional advantage of firing at one of the posse 
when three squares away diagonally. It will be 
seen, therefore, that it is quite possible for the horse- 
thief to be able to fire at a member of the posse 
without the latter being able to reply with a shot. 

Should the horse-thief succeed in reaching the 
defile he is well on his way to liberty, for on moving 
on to either of the three squares between the six 
squares banded with black “ in the mountains ” 
(which are supposed to be caves) the piece may be 
placed on the adjacent black-banded square and the 






248 Something to Make 

horse-thief may then cover with his “ gun ” all the 
six squares in the defile. That is to say, directly 
one of the sheriff’s men arrives within the defile 
the player representing the horse-thief may challenge 
44 Hands up,” and if six is thrown the pursuer 
is removed from the board. On the other hand, a 
member of the posse cannot return fire in the defile 
until on one of the three squares between the six 
black-banded squares. Of course, if any of the 
sheriff’s men pass through the defile without 
being shot (yet without shooting the horse-thief), 
the latter will have a difficult job to get through 
to the border in safety, the previous rules as to 
firing in the open still holding good on the other 
side of the mountains, except beyond the border. 

So, at any time when it is thought desirable, the 
horse-thief may be moved out of the 44 caves ” in 
which he took up his position and continue moving 
towards the border in the customary fashion, and 
should he succeed in throwing any number which 
takes him beyond the border-line the game is his. 

A man cannot be moved on to a square occupied 
by another, whether horse-thief or sheriff’s officer, 
and only one shot may be taken at a time. 

In conclusion, I should explain that moves may 
be taken in any direction —i.e. backwards, forwards, 
to right or left, or diagonally (by all men on the 
board), provided that it is in a direct line and the 
move can be completed. For instance, a move 
cannot be taken if it carries the man beyond the 
edge of the mountains, or, of course, beyond the 
boundary squares of the board, and if circumstances 
should arise to render such a move the only possible 








Miscellaneous Things to Make 249 

one it must be forfeited. Moreover, though the 
horse-thief may move through the woods (except 
on the corner squares thereof ), the posse cannot pene¬ 
trate the woods, being only allowed to occupy the 
corner squares (for the purposes of capture, as pre¬ 
viously pointed out). A six, be it remembered, 
never counts as a shot unless the player throwing 
it has previously challenged “ Hands up,” and in¬ 
dicates the piece he intends firing at, otherwise the 
throw is forfeited. Whenever the horse-thief is 
moving through the woods (when his moves are 
merely from square to square and not regulated by 
dice) the piece must be turned tree uppermost, 
and when, as before stated, in the open, vice versa. 

It may be thought that the game is a somewhat 
unequal one with six men against one, but this is 
not the case, the rules being arranged accordingly. 








HOW TO MAKE A DIVER 


HE diver is a scientific toy which can be made 



very easily in the manner described below, and 
a good deal of amusement may be derived from the 
experiment. 

The diver, as sold in the shops, consists of a glass 
bulb about J in. in diameter, out of which leads a 
short length of glass tube drawn out to a point and 
open at the end. The diver is filled with sufficient 
water to enable it to float just below the surface of 
the water in a bottle. 

By altering the pressure, either by pushing in 
the cork or by pressing on a sheet of rubber tied 
across the mouth of the bottle, the diver is made to 
descend. On releasing the pressure it will rise again 
to the surface. 

To make a simple form of diver, procure an 
ordinary pipette of the kind used for filling fountain- 
pens and remove the rubber. 

Next heat the glass tube at its centre in a gas 
flame (rotating the tube between the fingers all the 
time) until the glass softens, when it must be drawn 
out slightly, as shown in Fig. 1. Break the tube at 
a, first nicking it with a file, and you will have a 
shorter pipette, to which re-attach the rubber as in 


Fig. 2. 


The diver is now complete, except for the filling 
with water. It will be found that the best way to 
accomplish this is to take off the rubber, fill it with 
water, and replace it under water. Then carefully 


250 


K-I inch->| 

FIO. I 


FIC.2 


The Diver 


FIG.3 


Miscellaneous Things to Make 251 

squeeze the 
rubber to expel 
a few drops of 
water, allowing 
a bubble of air 
to enter. This 
should be done 
until the diver 
floats just 
beneath the surface of the water in the bottle. 

Now take a medicine bottle and fill it with water 
to the base of the neck. Place the diver inside and 
close the neck with a cork. If the diver is properly 
adjusted it will be found that it may be sent to the 
bottom by pushing in the cork. Fig. 3 shows the 
diver complete. 

The principle on which the diver acts is very 
simple. The pressure is transmitted through the 
liquid and forces a little more water up into the 
diver, making it heavier, and so causing it to sink. 

The diver may be so delicately adjusted that by 
pushing in or pulling out the cork the very slightest 
pressure is sufficient to send it to the bottom. 























HOW TO MAKE A CATAMARAN 

Its Uses in the East 


NE of the most curious of tilings that float in 



water is the Colombo fishing canoe which is 
styled a catamaran. To those who have had the 
opportunity of seeing them in the East they are a 
wonderful sight, and it is remarkable how the sailors 
control them, as the ordinary observer invariably 
pronounces them out of balance. 

Being of a light description and with an out¬ 
rigger similar to a torpedo, they can be classed as 
gliders, for they cut the water beautifully as they 
sail along. 

In use they are adapted for various purposes, 
such as pleasure sailing, fishing, and for cargo; and 
in regard to the latter, it is worthy of note that 
cattle are often carried. The crew can be seen sit¬ 
ting on the outrigger to give it the desired balance. 

The making of model boats has a strange fascina¬ 
tion, and the point which appeals is, will it float? 

The great point in model making is, of course, 
to make the model as the kitten is to the cat, or in 
other words, proportionate to the real object. 

Our catamaran is not difficult to make, and, more¬ 
over, it may be made without a lot of tools. 

In model boat building the ideal plan is to draw 
out the shape full size, along with any details, on 
either drawing paper or brown paper. A sketch is 
quite all right, but a detailed drawing is better. 

To make the hull, take a piece of kauri pine wood 


252 


Miscellaneous Things to Make 253 



and plane the piece up perfectly square. Scoop out 
with a gouge to the required depth, and the sections 
should be almost circular. 

Models of these canoes made in Colombo and 
sold to travellers and others have the hulls gouged 
out, and the side pieces are, as it were, stitched on 
with strong thin twine. 

The seats are fixed as shown in the details. The 
outrigger or torpedo-like beam, which floats in the 
water, can either be wrought with the chisel and 
plane or made in a lathe. 

In the actual ones, the Colombo fishermen balance 
themselves on the outrigger, though often they get 
a good drenching as it cuts through the water. 

The cross-rigger stays, c, c, should be made out of 
cane, as the same can easily be bent in a gas flame. 
The cross-riggers are secured to the deck by length 
poles, d, d, and twine. The method of making a 












































254 Something to Make 

full-sized one is the same as building a model one; a 
suitable size for the latter is about 3 ft. in length, 
2 in. inches across and about 3 in. deep from deck 
to bottom of hull. 

Make everything in connexion with it as light as 
possible. The construction is full of interest right 
up to the time when you give it the trial trip. 

In case kauri pine cannot be procured, yellow 
pine will answer the purpose. 





A CHESS AND DRAUGHTS TABLE 


T HIS table consists of four 1 J~in. square legs, 
having their outer faces tapering downwards 
to | in. square at the bottom. The upper ends of the 
legs can be sub tenoned or do welled to the table-top, 
which will be described later. At a height of 1 ft. 
4 in. above the floor, they are notched to receive a 
square framework of lf-in. by f-in. stuff, mitred and 
halved or tenoned as at a in Fig. 7, which shows an 
angle cut out to suit the notch on one of the legs 
(indicated by dotted lines). This framework should 
finish flush with the legs, and is partially shown at 
plan on b in Fig. 8. This figure shows how, by means 
of small quadrant mouldings c, mitred round each of 
three sides, the sides of the cupboard can be fixed in 
position as at d without the necessity for grooves or 
rebates. These sides can be | in. or even less in 
thickness, and when they are in position, a thin 
bottom, as at e in Fig. 5, can be fitted, its front edge 
serving as a stop to the door. 

The door should be made to match the sides, 
with a moulding mitred round its outer edges, and if 
the small internal drawer is required, it must be hinged 
so as to open right back (see Fig. 4), and leave this 
free to be pulled out without encountering any 
obstruction. 

The table-top can be a f-in. board with moulded 
edge projecting about 1 in. beyond the legs and having 
a quadrant mould fixed to its underside, as in Fig. 6, 
in which case the light and dark squares would 

255 


256 


Something to Make 


probably be stained 
or painted on it. 
For a more elabor¬ 
ate piece of work, 
however, the ar¬ 
rangement shown 
in Fig. 5 would be 
preferable. Here 
the squares are each cut 
and fitted separately, in two 
contrasting woods, such as 
sycamore and mahogany, 
and glued to a deal base¬ 
board f, the edges being 
finished with a larger 
moulding than in the 
simpler case, mitred round as shown. 

A possible addition to the table would be a couple 
of thin hardwood slides 



Fig. 1.—Table complete 


to pull out from under 
the cupboard to take the 
captured pieces of each 
opponent. These could 
slide in strips of brass 
bent and screwed in 
position as at g in Fig. 
2 on opposite sides of 
the table, and should 
have small stops on 
their undersides t o 
obviate any chance of 
being pulled out too 
far. 


T 


t 


T 


■x 




I 


Fig. 2.—Front 
view without 
cupboard door 


— If 


7 



























































pjg 7 # —Corner of Fram 
ing below cupboard 



Fig. 4.—Plan through 
cupboard 



Fig. 6.—Simpler form 
of top 



Fig. 8.—Angle of 
cupboard 


Q 


257 





























































































































SHELTERS FOR OUT-OF-DOORS 


I NEVER yet met the boy who does not enjoy 
hut-building and “ bivvy ” making out-of- 
doors. To be able to build your own shelter is not 
only useful work but great sport into the bargain. 
In a few moments the trained backwoodsman is able 
to set up a shelter which will keep him dry and warm 
for a night in the open. Every boy can do the same— 
if he knows how. I propose to give you some useful 
tips on hut-building and “ bivvy ” making. No 
doubt if you make a good one you will want to spend 
a night there with a pal or two—so here is a way of 
camping out with no tent at all ! 

In order to set up a good one-man bivouac you 
should carry with you the following articles :— 

2 rubber ground-sheets. 

1 sleeping-sack (or 2 blankets). 

1 good small axe or hatchet. 

1 box of matches. 

Plenty of strong twine. 














Miscellaneous Things to Make 259 

This sketch shows you the construction of the 
Backwoodsman’s Bivouac. With your axe you cut 
two forked sticks and point the ends. Drive them 
firmly into the ground about six feet apart. Now 
cut a cross-bar seven feet long and lay it across the 
forks. Cut three long poles for the lean-to and 
point the ends. Rest them against the cross-bar— 
one in the centre and one at each end—and drive 
them into the ground, then lashing the cross-bar, the 
fork and the lean-to rods together with twine. Next 
spread your ground-sheet over the lean-to framework 
and tie it to the poles with twine. Peg it out with 



How to thatch with sods : Start at the eaves and work 

to the top of the roof 

three pegs at the back. Cut and make your own 
pegs. Now place your other ground-sheet on the 
ground under your shelter, and on this roll out your 
sleeping-sack or blankets. You should then go off 
for the 44 night-log,” and place it on two smaller logs 
at each side (see sketch). Light your cooking fire 
and cook your meal. Turn in at nightfall, and let 
the fire eat slowly into the 44 night-log ”—this will 
keep you warm at night. Be certain that you have 
pitched your bivouac with its back set to the pre¬ 
vailing wind. In this country the prevailing wind 
is generally from the west. To find out the prevail¬ 
ing wind on your camping site, look for trees which 
grow leaning over towards one direction, or hold up 
your first finger after first wetting it in your mouth— 












260 Something to Make 



=§R» bunch of grass and 
watch how it falls— 
this also gives you 
the wind direction. 


the cold side of your 
finger is the wind 
side ; or throw up a 


Wattled Hut 


FfUVAfcVJOiR^. 


Of course, you will be able to think out all kinds 
of dodges for bettering your bivouac and making it 
more comfortable. After spending the night under 
it be certain to clear it away, and so clean up the 
ground after you that no one could tell that anyone 
had camped there. This is a great point in good 
camping and woodcraft, and the real pioneer and the 
natives are wonderfully clever at leaving no trace 
of their resting-place behind them as they move on 
across country. Burn all rubbish which will burn, 
bury old tins and replace the turf. But clear up 
after you, anyhow. 

The next sketch shows you how to construct a 
hut with “ wattled ” walls and “ thatched ” or 
“ tiled ” with sods. The “ wattle ” is simply pliable 
twigs twisted and woven like basket-work in and out 
of upright sticks. You must always be careful to get 
permission to lift 


reeds or sedges, or 
dead fir branches. 


can’t “ tile ” it with 
sods, try bracken, 
heather, dry grass, 


sods—don’t risk tak¬ 
ing them. If you 



HUT 





















A MODEL RAILWAY IN THE GARDEN 


W E are going to describe how a permanent 
model railway may be constructed in a quiet 
part of the garden where it is not likely to be inter¬ 
fered with by the gardener or other children, and 
where it may be left instead of being taken to pieces 
after we have amused ourselves with it. We shall 
also describe its equipment; that is to say, signals, 
turn-tables, running sheds, stations and other things 
which are necessary before trains can be conveniently 
and safely run. 

Our railway will possess its own docks, cranes, 
barges, and ships, and perhaps even a train ferry 
carrying trains from one country to another. 

Any reader who succeeds in interesting his father 
in our scheme will probably find him as enthusiastic 
as himself and, what is more, ready to provide the 
£ s. d. for carrying it out. The cost will not be great, 
because we hope to show how most of the things 
required may be made better and cheaper at home 
than if purchased at a shop. 

In a secluded part of the garden we will suppose 
the ground to be level (although the more uneven it 
is and the more banks and rockeries the better). As 
a railway on level ground would be uninteresting, we 
must first proceed to dig holes over it at random and 
pile up the earth so that the ground consists of little 
hills and valleys, taking care first to remove the 
turf in sods, which should then be replaced on the 
altered surface of the ground and rammed or patted 

261 


262 Something to Make 

firmly in place with a spade, so that it may grow again. 
The grass should then be neatly clipped. Whilst 
doing this, it is better not to think about where the 
railway will run. 

From one end of the ground to the other cut a 
channel, say, 9 inches deep and varying from 10 to 15 
inches wide. This channel should be made to wind 
in and out among the hills, and it must have a very 
regular, gentle slope downward to p. The slope may 
be easily regulated by an ordinary spirit-level, the 
bubble of which should be close to the centre on the 
side farthest from p, when the spirit level is laid in 
the bottom of the channel. Beyond p dig out a hollow 
space a yard or two wide and as long as the ground 
permits and about 9 inches deep. 

Now line the bottom and sloping sides of the 
channel and hollow space with gravel, ramming it 
firmly in place, and sprinkle coarse clean sand over 
the gravel so as to fill the spaces between the stones. 
Next mix some cement with sand and water (using 
about 1 part of cement to 3 or 4 of sand) so as to 
make a good heap of cement paste, sprinkle a little 
water over the gravel and sand (only just enough to 
damp it), and then spread the cement paste over the 
sides and bottom of the channel and hollow space. 
This is best done in the evening, when it is not likely 
to rain. By the morning it will have set, and in a 
day or two will hold water. Water may then be 
poured into the channel at one end and should flow 
very slowly towards p, filling the channel and the 
excavated basin, which we may then regard as a 
river and the sea. 

The distance from the City c to the Port p will 






Miscellaneous Things to Make 263 

clearly depend upon the extent of ground available. 
Fifty yards or more would be a good length, but even 
fifty feet or less will do. The plan need not be exactly 



Station 


Tunnel 4-long- 


Station 


Station IX 


Station F 


IpidgzI 


‘Station 


Station; 


—- Bridge TV^ 

_J?tat iotfvT \ 


Tunnel 


ItatioiI k" 


Station L 


llETlNG 

Bridge 


Complete Plan of Model Railway 
















Something to Make 


264 



followed, and 
if the ground 
is not long 
enough, the 
lay-out of the rail¬ 
way may be differ¬ 
ently arranged. Of 
course in a very 
small piece of 
ground, the river 
need not be made 
so wide. 

According to the size and condition of his ground 
each reader must exercise his ingenuity as to the best 
lay-out for his railway. 


Diagram showing escarp¬ 
ment cut round side of hill 


* * * * * 


The object of a railway is to connect two distant 
places and to take in on the way any intermediate 
towns and cities. This means that a railway is sel¬ 
dom built in a straight line, but curves first to the left 
and then to the right, so as to pass through the inter¬ 
vening places. Let us imagine that on our ground 
there are two cities, one of them a Port p, and the 
other an inland manufacturing City c, and that 
between them, but not in a straight line, are a number 
of smaller towns through which our railway will 
have to pass. We may also, if we like, think of one 
or two seaside places. 

We must now survey our ground to find out what 
obstacles there are, and consider the best way to over¬ 
come them, and of making our railway as level as 
possible, so that the maximum gradient is not steeper 










Miscellaneous Things to Make 265 

than 1 in 100; that is to say, that the steepest incline 
is not more than a rise of 1 inch in a length of 100 
inches. We will assume that our railway will be 
single track, with only one set of rails, and we must 
fix upon the gauge, or distance between the rails, and 
find out the size of our trains. In making a real 
railway, the ground has to be bought, and conse¬ 
quently earth for making embankments for the most 
part has to be obtained from where cuttings are 
made. In the case of our model railway, there is no 
need to worry about this, although it would be found 
interesting to those who can spare time to work it 
out. 

First stretch a cord between c and b, and we find 
a hill in the way. It is such a big hill that a cutting 
or tunnel would cost too much money, and it will 
be cheaper to make the railway curve round the hill, 
even though it means making it rather longer. 
Measure the distance between c and b round the side 
of the hill with a tape measure, and then find the 
height of c and b above water level in the river. We 
will say that c is 6 inches above water level and b 
9 inches, so that b is 3 inches higher than c, and 
that the distance between them is 100. Now with a 
gradient of 1 in 100 our line must not rise more than 
1 inch, and therefore railway station b will not be at 
the same level as c, but 2 inches below it, or 7 inches 
above water level. Having thus fixed the height 
and position of b station, we proceed to cut an 
escarpment round the side of the hill, which means 
that we slice out the hill-side with a sharp turf-trim¬ 
mer or knife (see illustration), so as to form a ledge 
on which our railway may be laid. The curve must 









266 Something to Make 

be made the same as the standard curve lengths of 
rail. 

Now stretch a cord from b to d, and we find a 
hill in the way which is too high to make a cutting 
through and too long to skirt as we did the first. 
Therefore, we must make a tunnel through it which 
had better be one inch higher and two inches wider 
than our trains. Before commencing the tunnel, 
find out the difference in level between b and n,. 
and see how near our railway can approach d with¬ 
out a steeper gradient than 1 in 100. Let us suppose 



they are the same height; then the line between 
them will be level. If between b and the side of the 
hill there is a valley, we must make an embankment 
across it, and this will best be made with turf neatly 
cut into shape with the grass on the outer sides of 
the slopes. To make the tunnel, take a tin canister 
without a lid, fasten a round piece of wood about 1 inch 
thick to the closed end, and fasten a stout bar of wood 
to the round piece (see illustration). With this a hole 
may be cut right through the hill. Each time the 
canister becomes full of earth it must be withdrawn 
and cleaned out. The canister may be somewhat larger 
in diameter than the inside width of the tunnel. 

Before boring the tunnel, however, we must 










Miscellaneous Things to Make 267 

make the lining for it. In making a real tunnel 
through earth, when the workmen have excavated 
a certain quantity of earth they build up a lining of 
brickwork, concrete, or iron all round the inside ; 
but, as our tunnel is too small, we must make our 
lining outside and fit it in afterwards. To do this, 
we shall require two thin sheets of metal, each slightly 
longer than the tunnel. Bend these round so as to 
form two hollow cylinders, one slightly smaller 
round than the tin canister, and one the same diameter 
as the width of the tunnel. Several tin canisters 
fastened end to end would do equally well, provided 
that the closed ends of the larger ones were cut out. 
Stand the two cylinders so formed in an upright 
position on a board one inside the other, and with 
a J-inch space between them all round. Now bend 
a piece of £-inch mesh wire netting of the same 
length as the cylinders, so that when placed between 
the cylinders it lies about mid way between them, and 
place two strips of wood as shown in the diagram. 
Mix one part of cement with four parts of clean sharp 
sand and enough water to form a thin paste which 
will just run, and pour this paste in between the 
two cylinders, so as to cover the wire netting, and to 
fill the space behind the piece of wood. 

When the space between the cylinders is full, 
leave them for a week in a shed to dry. Then pro¬ 
ceed to bore the tunnel as already described, and 
when the hole is made, push the tunnel lining into it, 
first removing the two pieces of wood ; the soft earth 
of the hill will soon settle close round the lining, 
which may be trimmed off at each end of the 
tunnel. 






268 Something to Make 

From d the line is then made to E, and assuming 
that there is a small hill in the way, we may make 
a cutting through it, with a sharp spade, a turf 
trimmer, or a knife. 

Between e and f the railway has to cross a river, 
and here we shall have to construct a bridge. 

Of course, two sets would be better for those who 
can afford them. If a double track is decided upon, 




Diagram of Implement for Boring Tunnels, mentioned previously 


all the cuttings, embankments and tunnels would 
naturally have to be made wider than for a single 
line. 

We now have to construct our first bridge, and 
we will suppose that where it crosses the river the 
latter is 15 inches wide. As the line sloped up 
1 inch from c to b, and down 1 inch from d to e, it 
follows that e is the same height as c, namely, 
6 inches. And assuming that the line will be level 
from e to the bridge, the level of the bridge floor 

























Miscellaneous Things to Make 269 



Diagram illustrating Method of Erecting Walls for Bridge 


must be 6 inches above the water. On each side of 
the river we must construct a wall (called an abut¬ 
ment) across the end of the embankment. This we 
may make of cement and sand (see illustration), 
making the walls about 1| inches thick at the top 
and 3 inches at the bottom, where they must be 
embedded a few inches in the soil, say 9 inches deep, 
making the walls slightly less than 15 inches high. 
The walls should be 24 inches apart. At ground 
level a sloping step or ledge with a rough surface should 
be made the full length of each wall. 


Wire Netting 



Diagram of Completed Bridge in position 


































270 Something to Make 



A stiff piece of cardboard should now be bent into 
a curve, the two ends of which bear against the walls 
just beneath the ledges. The top of the curve 
should be 5 inches above the water. Cut two more 
pieces of cardboard so that one edge of each is straight 
and the other edge curved to fit the curve of the 
arched piece. Then cut two more, each with one 
straight edge and the other edge curved and cut 
away 1 inch more than the other pieces. Smear 
the surfaces with soft soap and fasten them all 
together, as shown. They may be stitched together 
with thread. Now mix a quantity of cement and 
sand into a fairly stiff but moist paste, plaster the 
top of the arched cardboard to a thickness of \ inch, 
lay on this a piece of J-inch mesh wire netting curved 
the same as the cardboard, and complete the plaster¬ 
ing to a thickness of 1 inch. Before it is dry, fill in 
the two upright spaces between the other pieces of 
cardboard with the cement paste, pressing it gently 
in so that it will form a continuous mass with the 
floor of the bridge. When finished, cover it so as to 
protect it from the sun and rain for a day or two, and 
then remove the cardboard, and we shall have a 
reinforced concrete arch bridge complete with para¬ 
pets. To finish it off, partly fill in the hollow spaces 
between the crown of the arch and the two walls 
with a mixture of small gravel and sand, and finish 
off level with a covering of cement paste \ inch thick, 






























Miscellaneous Things to Make 271 

so that the bridge platform is level from end to end. 
Those who wish to could try their hand at ornamenting 
the parapets. 

The next town F is on the side of a hill, and we 
must incline the railway upwards, making a cutting 
through the hill. From f the line will incline down¬ 
wards to g, and in this section it has to cross the river 
again. In this case we will construct what is known 
as a trussed girder bridge. For this purpose we re¬ 
quire two pieces of planed wood, 4 inches wide by 
J inch thick, and another piece 6 inches by J inch, 
all, say, 24 inches long. On the four-inch strips 
mark out the lines shown in diagram, bore holes in¬ 
dicated by circles, and cut out the portions which are 
not shaped with a sharp chisel or with a fretsaw. 
The top and bottom strips which are left are called 
the girder booms or flanges, and the upright and 
diagonal are the vertical and diagonal web bracing. 
When a train passes over a bridge the diagonal 
members are stretched, and the upright members 
compressed, and as the diagonal members will be 
stretched across the grain they might break. We 
must, therefore, reinforce them by strips of metal, 
which may be cut out of a tin box with an old pair 
of scissors and screwed on each side of all the diagonal 
members, as 
shown. When this 
has been done, the 
6-inch strip, which 
must be perfectly 
flat, should be 
beneath 
the edges of the 
























272 Something to Make 

other two and screwed firmly to them at intervals of 
about 4 inches. After that the girders and flooring 
should be painted three times. 

The walls on each side of the river will be 21 
inches apart at the top, and will be constructed in 
the same manner as those of the first bridge, but 1 inch 
less in height. They should be finished off on the top 
by strips of lj inch by 1 inch well-painted wood, 
which must have a few nails driven through them 
and bent over so as to bed in the cement wall before 
it dries and prevent the wood from shifting. The 
girder bridge may then be placed in position and 
screwed down to these strips—two screws at each 
end of the bridge will be sufficient. 

Another type of bridge, known as the tubular type, 
like the great bridge across the Menai Straits, is very 
easily made from a strong wooden box deep and wide 
enough to hold a train with a 1-inch space all round, 
and long enough to suit the distance across the river. 
The two ends should be removed, the cover screwed 
on, and the sides and bottom screwed together in 
addition to being nailed. Then three good coats of 
paint, and we have our tubular bridge ready to erect 
on its walls or abutments. 

The remaining bridges, tunnels, cuttings and em¬ 
bankments will be constructed in the way already 
described, the young engineer using his discretion 
according to circumstances, because, as previously 
pointed out, we are only describing a typical railway, 
and it is for each reader to apply the lessons to his 
own particular case. In laying out our line, we must 
bear in mind the standard lengths of curved and 
straight rails. 








for Rail 


Iron Bar with square edges filed 
down and countersunk holes drilled 
for screwing to wood Sleepers 


/ Miscellaneous Things to Make 273 

If the reader 
has not already 
done so, he has 
now to decide 
a very moment¬ 
ous question, 
namely, 
whether he is 
going to oper¬ 
ate his railway by clockwork, steam or electricity. 
This we cannot decide for him, as it depends to some 
extent upon his taste, and still more upon his purse. 
If he settles upon clockwork trains (and there are 
very good English-made clockwork trains to be had), 
his track and equipment may be of the usual type, but 
in that case the track will need to be taken up when 
not in use, or it will very rapidly rust. If he decides 
on steam or electric locomotives, the gauge should be 
decided upon according to the length of his line. To 
keep everything as nearly as possible in proportion > 
we suggest that the smaller the gauge the better, 
especially on a small plot of ground. On the 
other hand, we do not want steam locomotives so 
small that they will not complete a full journey. 
They ought to be able, if possible, to make a 
double journey and still have steam in hand. 

Next to clockwork, 
steam locomotives will 
be found the cheapest 
in first cost, as they 
do not necessitate a 
«. 'ru- j r, c * „ , . „ . . third rail like electric 

“ IhirdRail bystem, showing third . . 

Rail supported on Insulators trams Or batteries for 



R 






















274 Something to Make 

supplying power. But as a railway with steam loco¬ 
motives means chasing the locomotives when we want 
to stop them, we shall take for our purpose the case 
of an electric railway. This is undoubtedly the most 
fascinating of all, because we may sit down at one end 
of the line, and by means of little levers control all 
our trains wherever they happen to be. Thus, 
supposing a train to start from one end, we may allow 
it to run right away to the other end and there stop 
it, or even reverse it simply by moving a lever, or we 
may stop it at any intermediate station and start it 
again by moving other levers. And our signals, 
points and crossings, and turn-tables may be con¬ 
trolled from the same point. 

There is another reason why it is better to have 
an electrified line. Electricity is the coming thing. 
Our young readers will live to see the day when steam 
locomotives will be looked upon as ridiculous mon¬ 
strosities of the past—much as we now look upon 
Stevenson’s “ Rocket.” Some day everything will 
be done by electricity and wave power. 

In a real electric railway there are several ways in 
which the electric current is conducted along the 
line so that it may be collected by a train. In each 
case, either on each locomotive or on certain coaches 
called “ motor coaches,” an electric motor is fitted 
and geared to the driving wheels. When the driver 
moves a lever it admits the current to the motor, 
causing it to revolve rapidly and so start the train. 

On some railways the current is conveyed by 
overhead bare copper wires against which a cross¬ 
bar on top of the motor coach is kept lightly pressed 
by a spring. The current passes from this bar 






Miscellaneous Things to Make 275 

through insulated wires or cables to the driver’s 
lever box and thence into the motor, after which it 
passes into the rails on which the rolling stock (that 
is, the engines and carriages) runs. Then it disap¬ 
pears into the earth. On other lines the current is 
conveyed by a rail laid between or just outside the 
track rails and is collected by what is called a slipper 
or metal shoe, which is lightly pressed against 
the third rail by a spring. After being collected the 
current works the motor as already described, and 
disappears through the track rails into the earth. 

There is still another system in which there are 
two extra rails, one from which the current is collected 
and the other into which it passes after working the 
motor. However, we shall ignore this system, also 
the overhead wire system, and confine ourselves to 
the single extra rail, which is known as the 44 third 
rail system.” As the third rail has to conduct the 
electric current it must not be spiked or screwed 
down to the sleepers like the track rails, but has to be 
supported on little pedestals, called insulators, which 
prevent the current escaping from the rail to the 
earth before it has passed through the motor. 

We have now to decide upon the kind of track 
rails and sleepers to use. On our model line this 
question is of as much importance in its way as the 
same question is to railway engineers, who give a 
very great deal of time and thought to the matter 
on real railways. 

Those who intend to go in for clockwork trains 
will find that the lengths of tin-plate track, in which 
the rails are already fixed to thin metal sleepers, 
are the cheapest to buy, although if left out in the 





276 Something to Make 

rain they will soon rust badly. These tin-plate rails 
can be greatly strengthened and improved by pur¬ 
chasing a quantity of well-fitting wire and fitting it 
in the hollow rail heads from end to end. 

Those who can afford it w'ould do best to buy the 
model steel rails and chairs supplied by Bassett- 
Lowke and other firms. Nevertheless, we will 
describe how straight and curved steel rails, which 
will serve the purpose equally well, may be made at 
home by those who possess a vice, a hack saw and 
small pillar drill or lathe. 

First, it will be necessary to purchase from an 
iron merchant the necessary quantity of steel or iron 

r 3 ^-inch by T 3 ¥ -inch in 
t, but we may say at 
once that, although 
such bars are made, 

'''7 it is often difficult 

/ 

to obtain them at 
all. These must 
then be cut neatly 
to the lengths required by means of a hack-saw. 
Two of the square edges must be neatly filed so 
as to round them for their full length. Then at in¬ 
tervals corresponding to the spacing of the sleepers 
small holes with counter-sunk tops must be drilled 
right through from top to bottom, so that small 
screws may be used to screw each one down quite 
firmly to the sleepers. 

When shaping and cutting our rails from T 3 ^-inch 
square bars, the straight pieces must be cut in pairs 
to exactly the same length, so that when fastened to 
the sleepers all the joints in one rail are exactly 














Miscellaneous Things to Make 277 



the wheels bump over a joint the shock is the same on 
both sides of the vehicle, otherwise there would be 
first a bump on one side and then on the other, which 
would cause a train to sway about in a most unpleasant 
and even dangerous manner. But rails which are to 
be bent into curves must not all be the same length; 
those in the outer curve must be slightly longer than 
those in the inner curve, as shown on the illustration,, 
from which it will be seen quite readily that the 
outer rail is longer than the other. 


A simple way to obtain the correct curve is to 
screw two pieces of board together in the form of a 
T as shown, and screw a long thin strip at a. Bore 
two holes near the other end of the strip, and in each 
hole wedge a lead pencil with the point downward, 

so that the 
distance 
between 
the pencil 
points is 
the same 
as the 
gauge of 
the track. 
Then, mov¬ 
ing the 
strip to 



An easy method of 
bending straight 
pieces of rail 


Working dia¬ 
gram showing 
how curves 
are obtained 







































278 Something to Make 

and fro, the pencils will mark two curves corre¬ 
sponding to the inner and outer rails. Thus, 
supposing we want a curved length as long as from 
b to c, we have merely to draw a line from a to c, and 
b c will be the length of the outer rail, and d e the 
length of the inner rail. Any line from a to the curve 
is called the radius of the curve. 

One way of bending straight pieces of rail is to 
shape two pieces of iron to fit the jaws of the vice as 
shown. If a straight piece of rail be placed between 
them, when the jaws of the vice are tightened the 
rail will be bent to a curve for part of its length. It 
may then be shifted, and the operation repeated 
until it is curved for its full length. After that 
it should be tried against the curve on the T board, 
and adjusted until the curve is exactly right. With 
a fairly strong vice the rails may be curved cold 
without heating them. Having set off on the T 
board the exact length of curved section required, 
the rails may be marked and cut to the correct lengths, 
and finally drilled to suit the spacing of the sleepers. 
After the rails have been screwed down to the 
sleepers, if any part of a screw-head projects it must 
be carefully filed flush with the top of the rail. 

Making your own rails will be found quite an 
interesting occupation once you have got into the 
way of it. But it is undeniably a long job and re¬ 
quires certain tools ; it may be difficult to obtain the 
steel bars, and even when finished the result is not so 
realistic as the beautiful little model rails and chairs 
that may be purchased. 

Having made or purchased our rails, the next 
thing is to contract for sleepers. This is a very simple 





Miscellaneous Things to Make 279 

matter. First we require a flat board screwed firmly 
to a table as shown, or the table itself would do quite 
well. Along the top edge of the board, commencing 
at the right-hand edge, mark off a scale in inches 
(including J and \ inches). Then fix an upright 
guide firmly to the top edge at the right-hand end. 

We must now procure a supply of planed wood 
strip of a size suitable for the sleepers. Supposing 
the sleepers to be J inch wide by § inch thick, that 
will be the section to obtain in lengths of several 
feet each. We advise pitch-pine if possible ; soft 



The Track 
Ballasted 


Finished Track with 
Line and Sleepers 


deal is not nearly so suitable. Having decided upon 
the length of sleeper (which varies according to the 
gauge of track), we have simply to place the strip in 
position on our cutting board, push it along until the 
end is against the mark indicating the length re¬ 
quired, and then saw it off with a fine saw, using 
the upright post as a guide. Knowing the length 
of our line and the spacing of the sleepers, it is easy 

to calculate the number required. 

We will describe the best way to ballast and lay 
the track, although it must be remembered that the 
positions of stations and buildings, and of points and 
crossings and sidings, really have to be fixed first. 








280 Something to Make 

For the moment we will suppose that this has been 
done. 

Ballasting a track means providing a layer of gravel 
or broken stone, or even burnt clay along a railway. 
On this layer the sleepers are placed, and then more 
gravel or stone is packed firmly round and in between 
the laid sleepers. Now the object of ballast is to 
prevent the sleepers from sinking into mud or clay 
when the weight of a train comes on them, and to 
allow rain-water, which would otherwise soak into 
the sleepers and rot them, to drain away; also to 
maintain the rails and sleepers in position. By 
degrees the ballast gets dislodged by the shaking of 
trains and the effect of rain and other things. The 
track of a railway is called the permanent way, and 
gangs of men tour the whole length of a railway to 
pack up the sleepers again as fast as the ballast 
shakes loose. 

Now in our railway we cannot use heavy stone 
ballast for our tiny sleepers, and if we ballast the line 
with ordinary sand, a single shower of rain may wash 
it all away. We shall, therefore, adopt another 
method, as follows. 

First, we shall require a heap of gravel and two 
sieves, one which will only pass sand through the mesh 
and another of, say, J-inch mesh. Use the J-inch 
mesh sieve first, and sift the small stuff into a separate 
heap, by itselsf. Now heat some tar in an iron 
vessel and mix it up with the small stones until they 
are well covered, and then pour off the tar. 

Before doing this the line should be marked off 
by strips of wood placed about an inch farther apart 
than the length of our sleepers. When the stones 






Miscellaneous Things to Make 281 

have been well tarred, lay them between these strip, 
of wood to a thickness of inch along the whole line. 

When the rails have been fixed to the sleeperss 
both sleepers and rails should be well coated with hot 
tar and laid upon the bed of tarred stones. The 
curved portions of the track should be laid first, and 
the straight lengths should be fitted in between the 
curved portions. When everything is in correct align¬ 
ment and levelled up, more tarred stone should be 
filled in between the sleepers to the level of their top 
surfaces and pressed gently into place. By this 
means we shall construct a permanent waterproof bed 
of ballast. A realistic effect may be obtained by 
sprinkling plain sand over all the sleepers and ballast. 

Tar is of course nasty, messy stuff to handle, and 
it will need some practice to tar the stones properly 
and not leave too much tar. Those who do not care 
to do this have the alternative of purchasing a barrel 
or two of small tarred stones from a road contractor. 






A CRICKET BAT CASE 

CASE of canvas or baize with a buttoned flap 
helps to keep a cricket bat in nice condition 
while lying about, and is very easy to make. First 
mark out the material with chalk, as shown by Fig. 1, 
laying the bat on it as a pattern, and allowing about 
1-J in. margin all round, besides sufficient for the 
flap a at one side. To get both sides alike, the 
material may be folded if desired. 

Having cut it out, run round with a needle and 
thread, as in Fig. 2. Then turn the bag inside out, 

and trim the 
now uneven 
flap portion 
level with the 
sides. Get 
some binding 
tape of any 
pleasing col¬ 
our, or leather 
strip, if pre¬ 
ferred, fold it 
in half over 
the edges and 
stitch it on 
round the bag and flap, as well as at the opening. 
Sew on the button, then mark the place for the 
buttonhole in the flap, cut it, and edge it round 
with binding tape. Fig. 3 shows the finished bag, 
with the flap raised. 





282 




























THINGS FOR CAMP AND TREK 


r 1 A HERE is something very attractive about the 
word “ pioneer.” There are the pioneers of the 
Army, fellows whose job it is to pave the way for the 
troops in the rear, to build bridges so that they can 
cross rivers, to clear camp sites and so on. And there 
are the pioneers who enter unexplored countries 
to pave the way for the settlers and civilization. 
There are pioneers in every walk of life, fellows who 
spend years in study and research in order to perfect 
some particular science, etc. 

There are boy pioneers, too. These are the chaps 
who practise the stunts of the pioneers of old, because 
they realize that to be able to do useful things in the 
open may be of great service to them in after life, and 
also because there is real pleasure in pioneering. 

Years ago when boys first went to organized 
camps they used to take chairs, usually borrowed 
from the Sunday School, upon which to sit when they 
had their meals or wanted to rest. But nowadays 
the regular camper would never dream of taking a 
chair with him. He would make one on the spot, 
and this is how he would do it. 

He would select a tree about nine inches in 
diameter and, after getting permission from the owner 
of the ground, would proceed to chop it down. First 
he would clear away the underbrush around the tree, 
so as to leave a clear space for the swing of his axe, 
and the branches of the tree up to a fairly good 
height, then he would decide which way he wanted 

283 


284 Something to Make 

the tree to fall. This, of course, would depend upon 
the trees in the immediate vicinity. If a wind were 
blowing he would always fell the tree with the wind. 

We will suppose that he wants the tree to fall to 
the right. He would cut a notch with his axe on the 
right hand side of the tree a little more than half-way 
through the trunk, shown A in the sketch. The 
notch would be made fairly large so that the axe would 
not wedge. Having made the cut deep and large 
enough, he would then start to make the notch 
marked B in the sketch, which you will notice is made 
a little higher than the first. 

When the support between A and B becomes too 
slender to hold the weight of the tree it will begin to 
waver at the top, and that is the signal for the axeman 
to step to one side of the tree. The tenderfoot might 
make the mistake of standing behind the tree as it 
falls, but he would never forget the lesson the butt of 
the tree would teach him if it happened to kick. The 
correct thing to do is to stand well to the side. 

The tree is down now, and our axeman will 
next trim off the branches close to the trunk. This 
done, the log is ready for turning into useful camp 
furniture. 

To make the chair he will cut off a length about 
two feet. This he will stand on end and cut down 
and across, as shown by the dotted lines in the second 
illustration marked A. After trimming this and 
making the seat smooth the chair is finished as in 
sketch B. 

By cutting another length of suitable height, when 
stood on end, he can provide himself with a “ one man 
table.’ * 








Miscellaneous Things to Make 285 


The good pioneer boy does not waste any wood. 
Any chips that are left after a job he will use to light 
his fire. The small branches he will use to make pot 
hooks as shown in the third illustration. All that is 
required is the small branch with a couple of nails, one 
fastened at each end as shown. 

With four small branches eighteen inches long and 
about an inch and a half thick, and one twenty-four 
inches long by an inch and a half thick, you can make 
a simple arrangement on which to hang your pot hooks 
over the camp fire. With two of the smaller pieces at 
each end of the fire and fastened into the ground in the 



manner of two legs of a tripod and secured with wire 
where they cross, you form a rest for the longer piece. 
Upon this long piece you can hang your pot hooks. 
The illustration will make this quite clear. The 
branches used for this should be green, so that they 
will not burn easily. 

With the longer branches from the tree you can 
make an Indian travois, a very useful contrivance for 
conveying gear about a camp. This is how you do it. 
First get two straight branches at least six feet 
long. Lay these on the ground fanwise, so that they 
cross each other at a point about eighteen inches from 
one end. Here you lash them together with stout 
cord. 
































286 Something to Make 

At about the same distance from the other end you 
lay another branch about four feet in length, and lash 
that firmly to each of the longer branches. By 
laying a heavy tent upon the travois, any boy can 
move it with ease to any particular place. 

The boy pioneer must, of course, know how to 
make a bridge. One of the simplest is known as the 
“ single lock trestle bridge.” It consists of two 
trestles constructed as shown in the sketch, and wide 



enough to meet, when placed in the position shown 
in the next illustration, across the river to be bridged. 

The trestle’s main points are two uprights and two 
cross pieces lashed together so that they form almost 
a square. The cross pieces must be lashed firmly 
to the uprights. For extra support two pieces in the 
form of a letter x are lashed into position as shown. 
If the trestle is lashed firmly it will be perfectly rigid. 

Having made the two trestles, they are locked 
together by simply sticking the broad end pieces into 
the side of the banks, and allowing the trestles to fall 
against one another in the form of an arch. If this is 














Miscellaneous Things to Make 287 


done carefully 
they will lock se- / w, 
curely. All that ~Jp§P 

. -manl 

remains to be done 1|§|v 


Planks 


Logs to male centre firm 



Two trestles locked 
from bank to bank 


now is to place 
planks of wood 
from each bank, so that they rest on the trestles. 
Such a bridge will bear great weight. 

The backwoodsman of the big woods takes great 
care of his axe. He does not throw it about un¬ 
necessarily. When he has finished his job he places 
a guard over the keen edge to protect it and also to 
prevent accidents happening. 

The boy pioneer will also take care of his axe. He 
will keep it clean and sharp, and put a guard on the 
blade when the axe is not in use. You can make a 
guard quite easily from a small piece of wood a little 
longer than the cutting edge. Cut a notch right 
down the wood deep enough to take the edge of the 
blade. If the blade is embedded in the wood it will 
form an effective guard. 

A leather guard to protect the whole of the steel 
axe head is easily fashioned from a piece of leather 
the length of the blade and double its width. Fold 
the leather in the centre and sew up the two sides, so 
that you make a sort of pouch. The top is left open 

















288 Something to Make 

so that you can insert the head of the axe. A small 
strap can then be passed round the outside of the 
pouch to keep it in position. 

When purchasing an axe buy a good one from a 
reliable maker. Don’t be put off with a little chopper. 
What you want is a real pukka felling axe. 

A lean-to shelter is one of the easiest to make. 
First you need a branch eight feet long or thereabouts ; 
this forms the main support. To build the shelter 
the branch is fixed in the crook made by a branch 
of a standing tree, not an elm, of course, because 
it is dangerous to camp beneath elms. 

Against this leaning branch you erect a framework 
of smaller and thinner branches and then thread 
brushwood under and over the framework. If you 
have a light canvas cover you can throw it across 
the lean-to branch, and by pegging it down at the sides 
you will have a respectable and comfortable tent. 


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